May Gardening Checklist

Annuals:

May is definitely the month for planting warm-season annual plants in your garden. The nights are consistently warmer, the days are longer and sunnier, and the thermometer is rising. Here are a few tips for planting and caring for garden annuals in May:

● Warm-season annuals should be in abundant supply in all sizes right now. Get them planted now before it gets too hot. They will establish a bit easier now than in July or August, and irrigations will be a bit easier as well. Choices for annual flowers include petunias, lobelia, verbena, marigold, ageratum, cosmos, impatiens, coleus, torenia, and begonias..

● If you need some real hot weather sizzlers, try dahlias, zinnias, gomphrena, cleome, portulaca, and lisianthus. These plants absolutely love the heat.

● Because of their quick growth and heavy flowering potential, annuals need more frequent fertilizing than most other plants in the garden.

● Keep deadheading (removing spent flowers) from annuals to encourage them to continue blooming abundantly.

● Plant hot-weather annual summer vines from seed now, like morning glory and moonflower.

Geraniums:

● This group includes ivy geraniums, zonal geraniums (also called “Common” geraniums), Martha geraniums, and the various scented geraniums, but does not include true geraniums (sometimes called “hardy” geraniums), which are discussed under ”Perennials.”

● Ivy and zonal types should be blooming well now. Remove spent flowers to the bottom of the stem regularly to encourage more blooms.

● Martha types should continue to be blooming well. Regularly remove spent flower clusters just below the flower to encourage more blooms.

●Ivy and zonal geraniums do not like heavy pruning. To keep the plants shapely and vigorous for a longer period of time, prune back a few long stems every month or so from now through fall, but never very many at one time.

● Fertilize all geraniums, except most scented types, regularly with a balanced fertilizer. Geraniums prefer a slightly acidic soil, so periodically alternate feedings with an acid fertilizer such as cottonseed meal.

● Rust may continue to be a problem in some gardens, especially on zonal and Martha varieties. However, it is usually only a springtime issue, and with the warm weather approaching, it should be coming to an end.

● Budworms may still be attacking the developing buds and new leaves. If necessary, spray with BT on a regular basis.

Sweet Peas:

● Your annual sweet pea plants should still be blooming wonderfully now, as long as you have been feeding and removing the dead flowers religiously. This deadheading may be as often as twice a week.

● Feed regularly.

● Assist them with climbing and support if necessary.

● They may be beginning to show a little heat stress, particularly at their bases where yellowing and drying will be noticeable.

For more information, watch & learn: World-Class Sweet Peas with Steve Hampson

Wildflowers:

● Most California wildflowers will be over their bloom peak and beginning to look a little stressed.

● If you want some of your wildflowers to re-seed for next year, leave them in place for a while and allow the seed to fall to the soil.

● You may be able to extend the wildflower season by a short time with additional irrigation, but the end is near for these beauties.

Poinsettias:

● Pinch the tips of the new growth on poinsettias (as long as it is at least 3-4 inches long) to encourage branching and more flowers.

● Fertilize poinsettia plants often with a well-balanced food to encourage growth.

● Watch for whiteflies and treat as needed.

Fruiting Plants

Strawberries and grapes are some of the best fruit plants to grow, and they’re working hard right now. It's time to start feeding them in earnest so they produce more delicious fruit.

Strawberries:

● Feed your strawberry plants regularly. Periodically alternate with an organic acid fertilizer, like cottonseed meal, to keep the soil pH low, which strawberries prefer.

● Bait, trap, or handpick snails and slugs regularly to avoid fruit damage.

● Strawberry fruit will be less likely to be bothered by pests or rotting if separated from the soil slightly. Use straw, pine needles, or rings cut out of unprinted corrugated cardboard.

For more information, watch & learn: How to Grow the Best Strawberries with Sarah Smith

Grapes:

● Grapevines should still be growing vigorously now. Train the grape canes as desired.

● The first fertilizer application should have been made when the new growth had grown a couple of inches. Assuming the use of a granular organic product, the second application should be six to eight weeks later (about now), the third application another six to eight weeks after that, and the final application in another six to eight weeks. Remember, use a well-balanced product that contains trace minerals, which grapes need. Organic products are usually a good choice.

● Irrigate regularly and deeply according to the soil and temperatures.

Shrubs & Vines:

In general, California shrubs and vines will be growing quickly now, and they may want to grow too large for their space. They may even want to grow into small trees. If that's what you want, let them be. But if not, you’ll need to clip them to restrain them. Pruning these shrubs is best done just following their bloom cycle, which should finish in early May.

● Hedges are growing like mad.

● If you haven’t already, this is about the last chance to prune winter- and spring-flowering shrubs and vines that have finished their bloom cycle for this year. These include pink jasmine (Jasminum polyanthemum), Hardenbergia species (lilac vine), jessamine (Gelsemium species), cat’s claw (Macfadyena unguis-cati), flame vine (Pyrostegia venusta), and wisteria.

● Don’t prune summer-blooming vines—these that haven’t flowered yet.

For more information, watch & learn: Hardy Flowering Shrubs with Dalia Brunner

Azaleas:

● Most varieties of azalea (evergreen and deciduous shrubs) are about finished blooming no. However, there are few summer bloomers.

● A light application of an acid fertilizer, like cottonseed meal, is ideal now as they enter into their “growth” season. In the ground, only two feedings per year are necessary. Your next feeding will be in September.

● Never cultivate under an azalea, or you will damage their delicate surface roots. A thick layer of organic mulch is a better idea.

● They don’t really require any pruning, but if you do need to shape them or reduce their size a bit, the best time to do it is shortly after they’ve finished blooming.

Camellias:

● A few Japanese camellia shrubs may still be in bloom. As soon as your camellia shrub finishes blooming, complete any necessary shaping or other pruning.

● You should be at the beginning, middle, or end of your camellia fertilizing for the year. Apply the first of three feedings to your camellia about 4-6 weeks after it finishes blooming. Use an “azalea/camellia” or acid-based fertilizer, like cottonseed meal. Apply a light application (camellias are not heavy feeders) evenly around the base of the plant, but do not dig it into the soil. The second feeding is 4-6 weeks later, and the final feeding will be 4-6 weeks after that.

● This is an excellent time to apply a layer of fresh, thick, organic mulch under your camellias. This mulch will keep the roots cooler during the warm summer months, improve the soil quality and reduce watering requirements. Carefully rake up any fallen flowers and, if fertilizing this month, apply the fertilizer first and put the mulch on top.

For more information, watch & learn: Gardening 101 Series | How to Plant & Maintain a Camellia

Gardenias:

● Gardenia plants should be budding and blooming well this month.

● Keep them well-fed through the summer months. Use a fertilizer with trace minerals, such as most organic types, and alternate this with an acidic formula to keep the pH down.

● If the leaves are showing yellow areas between green veins, especially on the new growth, they need additional iron. Iron is a supplement to the regular fertilizing program for your gardenias.

For more information, watch & learn: Gardenias for Southern California with Nicholas Stadden

Hydrangeas:

● Hydrangea shrubs should be growing nicely, and most will even be blooming..

● Apply a moderate feeding.

● Do not prune hydrangeas at all this time of the year. Hydrangeas bloom on one-year-old stems. Pruning now will eliminate most of the flowers.

● If you want to try to get blue or lavender flowers on your otherwise pink plant, you should make your final aluminum sulfate application to the soil (assuming your plant has not already bloomed). White-flowered varieties will not be affected, and not all pinks will be affected the same.

For more information, watch & learn: Re-blooming Hydrangeas with Nicholas Staddon

Roses:

● In most gardens, this will be the biggest rose bloom of the year. The flowers will be huge and the colors rich. The flowers will hold their form well in the May temperatures, and the foliage is lush and healthy as well. Enjoy the show.

● If you love roses, this is a great month to get out and visit other great public rose gardens. The biggest and best are at Rose Hills Memorial Park (Whittier) and the Richard Nixon Library (Yorba Linda).

● Roses are heavy feeders; continue fertilizing them regularly. Do not use soil-applied fertilizers combined with a systemic insecticide; these products are very disruptive to soil life (beneficial microorganisms, bacteria, mycorrhizal fungi, earthworms, etc.) Many rosarians also believe they reduce the vigor of the rose.

● Granular, well-balanced, organic fertilizers work especially well for roses, and most of these will encourage beneficial soil life.

● Keep deadheading roses as they fade. Cut them just above a leaf with five leaflets. Floribundas, many English roses, and some others are deadheaded on very short stems until the last of the flowers in the cluster have faded. Then cut down to just above the first leaf with five leaflets.

● Be on the lookout for pests. Aphids will be less of an issue as the weather warms up now and can usually be hosed off with a strong jet of water. Flower thrips may require an insecticide.

● Keep on the lookout for diseases. Powdery mildew and rust are the primary issues. In warm inland gardens, these are primarily springtime issues and in another month or so may disappear by themselves. Regular grooming, early removal of infested leaves, good air circulation, and full sun will help considerably.

● If diseases do require a fungicide, use one of the newer, safer, organic products available. These include Rose Defense (a neem oil extract), E-Rase (jojoba oil), or Saf-T-Side (straight paraffinic oil).

● Potted roses are still in good supply, and the selection is excellent now at our outdoor plant nursery. It is a great time to add more or upgrade any that you are struggling with

● Keep making notes in your garden journal about which roses are performing well and which are not. Notes on disease problems will be useful later if you decide to upgrade to an improved variety.

● One of the most obvious pests, especially in coastal gardens, has now shown up. Commonly called “rose slug,” it is not a slug at all, but the larval form of a fly relative called the sawfly. These little caterpillar-like pests are hard to spot but chew on the undersides of foliage. Eventually, the pest eats irregular holes through the leaves. Neem oil will work on them, as will organic pyrethrin sprays, but the applications must be thorough, frequent, and applied to the undersides of the leaves.

● Irrigations should be frequent now as the weather warms and the days lengthen.

● For the biggest flowers, pinch out some of the competing buds while they are very small..

● Hose off the foliage of roses frequently. Contrary to popular myth, this will actually reduce the likelihood of powdery mildew and keeps the foliage clean and healthy-looking.

● Weed as needed, but avoid most herbicides around roses.

For more information, watch & learn: How to Prune Your Roses With Laura Weaver, Bare Root Roses with Dalia, & How to Plant and Care for Roses

Wisterias:

● The month of May is the end of the main bloom period for wisteria vines. If you followed proper pruning protocol all year, the flower show should have been spectacular.

● For established plants, wait until next month for the first in a three-pruning-per-year cycle.

● On young plants, guide the long, twining stems carefully in the direction that you want.

● You’ll enjoy a better-looking plant if you prune off the dead flowers as they finish blooming. This will prevent unattractive seed pods from developing on the plant.

● If your wisteria has been planted for only a year or two, be sure to provide it with plenty of water and fertilizer to encourage quick coverage and deep roots.

● Established wisterias are better with only an occasional deep summer watering and little, if any, fertilizer other than possibly iron (to correct chlorosis). Wisterias are large, aggressive vines; additional water and fertilizer will only create more rampant growth and more pruning needs.

● Continue planting new wisterias now. If possible, choose them while in bloom. Grafted plants are preferred since they will almost always bloom at a much younger age.

Trees:

May is an acceptable month to prune tender sub-tropical and deciduous fruit trees like ficus, coral tree, avocado, citrus, et cetera. Most other trees are best pruned in late fall or winter. These sub-tropical trees should not be pruned during the cool winter months. However, care must be taken not to disturb nesting birds during this season. Pruning now may interfere with the flowering of certain species; here are few tips for the trees in your garden.

Deciduous Fruit Trees:

● As the weather warms, be sure to monitor the soil moisture and irrigate deciduous fruit trees as needed.

● Several varieties of deciduous fruit trees will “drop” a lot of their fruit about now or by next month. Don’t be alarmed; this is normal since the tree cannot usually support all of the fruit that it originally sets.

● The best time to thin any remaining fruit is right after the “drop” is completed. Emotionally, this is one of the most difficult things for a gardener to do and therefore often avoided. However, well-spaced fruit will develop into a higher-quality crop, and the fruit will be larger in size.

Citrus:

● Citrus are growing well this month, and a few may even have some flowers on them.

● Continue fertilizing citrus trees this month and every month from now until July. Use a fertilizer rich in trace minerals like iron, zinc, manganese, and copper. These ingredients are usually well-represented in organic fertilizers like Dr. Earth.

● Honeybees are pollinators for citrus. Encourage these beneficial insects and avoid anything that might discourage them.

● Be attentive to watering now that the weather is warming up.

● Kumquats should be ripe now.

● ‘Kara’ tangerines may be ripe by now or very soon. This is about the only summer-bearing mandarin and needs a warm inland location. Tangelos may also be close to ripe.

● Valencia oranges may look like they are ready to harvest but probably will not have developed their sugar content yet. Resist the temptation to pick them this early and let them sit on the tree for another month or two to develop their sweetness.

● If ants are crawling up the trunk of the tree, apply Tanglefoot (a sticky, waterproof substance) to stop them.

Avocados:

● Avocados are still growing well now, and the plants should appear to be in peak health for the year.

● Irrigate as needed to keep the soil moist but not wet.

● Most varieties will still not have fruit ready for harvest this early. However, some varieties, like ‘Gwen’ and ‘Whitsell,’ often have fruit at unusual times.

● May is a very good month to plant avocados. Being sub-tropical plants, avocados prefer to be planted at the beginning of the long warm half of the year.

● Don’t be alarmed by a lot of leaf drop if you're growing a mature avocado tree. Avocados produce a lot of leaf litter nearly year-round. This is a normal condition.

● Be sure to keep a very thick blanket of mulch, compost, or fallen leaves under mature avocados at all times. Avocados need a cool root-run for good health.

For more information, watch & learn: Edible Gardening: How to Grow Avocados in Southern California with Sarah Smith

Subtropical Fruits:

● Almost subtropical fruit trees are now awake and growing.

● This is a good month to begin serious plantings of these heat lovers.

● Fertilize with a general-purpose organic fertilizer. Most tropicals and sub-tropicals have a higher need for trace minerals like iron, zinc, manganese, et cetera. Organic fertilizers generally contain many trace minerals and work especially well in the warm soil temperatures present now.

● Watering should be frequent now, but most tropicals and sub-tropicals need to have quick soil drainage.

Perennials:

May is still a good planting month for perennials. The selection of perennial flowers is excellent, and many will be in bud or bloom. Be sure to keep them well-watered as these young plants head into the warm summer months.

● Keep fertilizing your perennial plants. The frequency and amount will depend upon the formulation that you are using. If you have been building up your soil health, your fertilizing duties will be significantly reduced.

● Most of your perennial “chores” should have already been done, and you can now enjoy your perennials in all their colorful glory.

● Sub-tropical perennials have perked up now and should be putting on new growth and maybe even buds and flowers. The best tip to remember is that May is a great month to plant heat lovers like begonias, heliotrope, impatiens, lamium, pentas (starflower), and plectranthus in your garden.

● Keep tying the flowering spikes of tall, upright, spiking perennials, like dahlia, delphinium, foxglove, true lilies, and monkshood (aconitum) to the bamboo stakes that you put in earlier in the year.

● Removing the myriad of spent or old flowers regularly always helps them to produce more new flowers. This is a good time to cut some fresh flowers for a vase as well.

For more information, watch & learn: Gardening 101 Series | How to Use Annuals vs. Perennials with Lynn Hillman & Gardening 101 Series | Pruning Lavender & Perennials with Dalia Brunner

Clematis:

● Along with April, this will be the heaviest blooming month for most clematis. Keep feeding them with a balanced organic fertilizer to keep them going. If your soil is slightly alkaline (high pH), periodically alternate an acid product, such as cottonseed meal, into your fertilizer routine.

● An important tip for clematis is to keep the roots cool and shaded wherever possible, but not the tops—especially as it gets hotter in the garden in May. Planting a small shrub or a couple of perennials just to the south side of the roots will help. In addition, apply a very generous organic mulch over the surface of the soil.

● Keep plants well-watered.

California Native Plants:

● A few California native flowers will still be blooming and growing, but most will already be slowing down and preparing for the long, hot, and dry summer months.

● Be very cautious irrigating most of our native plants during the summer. Most of these are adapted to a winter wet/summer dry moisture cycle. Frequent irrigations now (especially in soils with a clay content) will certainly cause problems.

For more information, watch & learn: California Native Plants for Your Garden with James Maxwell, Success with Native Plants with James Maxwell and All About Our Native Milkweed

Fuchsias:

● Your fuchsia plants will be in full bloom now!

● Keep fertilizing fuchsia plants regularly with a balanced fertilizer, or one slightly higher in phosphorus, to promote blooms.

● Keep plants well-watered, especially hanging baskets. You’ll need to water more than average during warm weather.

● Groom fuchsias periodically by removing dead flowers and any developing seed pods.

● Watch for fuchsia gall mites, which are a serious pest of these plants. Look for any signs of puckered or distorted new growth. If you discover any, pinch it out and dispose of it immediately. A pesticide treatment is usually required.

Groundcovers:

● Cool-season groundcovers are still blooming, but the heat will soon catch up with them—especially in warm inland gardens and on south-facing slopes.

● Warm-season perennial groundcovers have been waking up and are growing again and possibly blooming as well. If you didn’t last month, feed these now with a balanced, organic granular fertilizer.

● May is still a good time to perform a heavy cutting-back of warm-season groundcover varieties. Many groundcovers build up considerable thatch and lose their vigor if not cut back periodically. Hurry to get this chore done now before the weather heats up too much more. Be sure to fertilize after the cut-back to ensure quick recovery.

● California native groundcover plants, like ceanothus and arctostaphylos (manzanita), may still be showing some blooms. Although tempting, this is not a good month to plant these. Wait until late this fall.

● Although getting late, large-scale groundcover plantings can still be accomplished now. Be sure to mulch between the plants after the planting to help the plants establish, reduce weed growth, improve soil quality and reduce irrigations.

● Step up irrigations as needed, especially in sunny areas or on slopes.

For more information, watch & learn How to Plant & Grow Groundcover with Dalia Brunner

Orchids (Outside Grown):

● Cymbidiums are now done blooming and are entering their growing period. Once they finish blooming, switch their fertilizer to one with a high nitrogen fertilizer that is preferably free of urea.

● If pots of cymbidiums are excessively crowded and have a few leafless, brown bulbs showing (these are called “back bulbs”), it is time to divide and re-pot them. Many beginners are intimidated by this important chore, but it is really quite simple. Check a reference book or get a “how-to” sheet at a good nursery to learn the right procedure.

● A tip for orchids is to watch how much sun they’re getting in the garden in May. You might need to move outdoor orchids to slightly more shade. Now that the sun is higher in the sky and the days are longer, be careful not to sunburn your plants.

For more information, watch & learn Orchids and How to Care for and Maintain Phalaenopsis Orchids with Steve Hampson and How to Repot Your Phalaenopsis Orchids with Steve Hampson

Bulbs, Rhizomes, Tubers, Etc:

● The big burst of spring-flowering bulbs is now transitioning into warmer-weather species. Bulbs that will likely be in flower now in Orange County include some alliums, bletilla, calla, gladiolus, hippeastrum, some true lilies, ornithogalum, sprekelia, tigridia, tritelleia (highly recommended!), and Watsonia.

● As spring bulbs finish blooming, do not hurry to cut back the foliage or ignore the plant. Keep the leaves in place and continue watering until the leaves naturally turn brown and dry, then you can cut them off. These leaves are sending energy to the bulb for next year. Of course, for one-year bulbs—like most anemones, crocus, hyacinths, muscari, ranunculus and tulips—pull them and toss them out once they’ve finished blooming.

● Bedding cyclamen have been blooming for months but are about done in most gardens. Most gardeners pull them out; however, if they are in good, rich soil and protected from the summer heat and dry winds, they will struggle through the summer and return to flower this fall.

● Caladiums that were planted recently are now beginning to sprout. These love warm soil, warm nighttime temperatures, and long days, but not direct sun or wind.

● Plant new tuberose flowers now, or re-plant those that you lifted out last November and have kept in storage.

For more information, view Gardening 101 Series | How Do I Plant Spring Bulbs?

Bearded Iris:

● Most bearded irises are now in full bloom, and a few may have already even finished this flowering cycle.

● If you are growing any of the new “repeat-blooming” varieties, they may cycle again in as little as a month or two. Keep feeding these re-bloomers aggressively. Older “once-blooming” varieties can have their feeding reduced in half. Any fertilizer labeled for roses (by not with insecticides or other added ingredients) will do fine.

● Trim off the faded flower stalk just above the foliage when the last flower fades.

● If you need to add more irises to your garden, you can still do it now. Select blooming plants now and plant them; just be careful not to disturb the root system too much.

Dahlias (Tuberous Types):

● Tubers should be growing well now and the early varieties will be setting buds and maybe even blooming.

● For younger plants, be sure to pinch off the top set of leaves when the stems are about eight or ten inches out of the ground. This will encourage the plant to branch and have more blooms.

● Fertilize dahlias regularly throughout their growing and blooming period. Use a liquid or granular organic fertilizer that is low in nitrogen and high in phosphorus. Fish bone meal is excellent.

● Regularly cut off spent blooms to make the plants both look better and set more flowers.

● Keep the taller varieties carefully staked to prevent the heavy canes from toppling over. Heavy natural cane bamboo stakes work well.

For more information, watch & learn Lew Whitney's Secrets to Growing and Maintaining Dahlias

Cannas:

● The first flowers should be on your cannas now!

● Keep them well watered; cannas do not like dry soil.

● As cannas flower, you may notice that each stalk produces a cluster of flowers at the top. After this cluster finishes the stalk grows a few more inches and produces another cluster. In some varieties, this can go on for four or five clusters and last almost two months from beginning to end. When the last cluster of flowers has finished, cut the entire stalk to the soil. This stalk will never bloom again and cutting it down will encourage more stalks, and flowers, to grow. Keep this process up all summer for the best results.

Tuberous Begonias:

● Tuberous begonias should be growing well, and with a bit of luck, there may already be some buds appearing. Don’t worry too much about flowers, though. Right now you just want the plants to grow healthy and full. In fact, some gardeners pinch out the first set or two of flowers to focus more energy on the growth of the plant.

● Keep fertilizing regularly. They are heavy feeders, especially in containers. Use a well balanced fertilizer and periodically mix in an acid fertilizer, to keep the soil pH low.

● Keep them well watered, but not soggy. The soil should be rich and well-drained. The surface of the soil should dry slightly between watering.

● If powdery mildew appears, treat it by improving air circulation around the plants. Usually, this will correct the problem. If not, use a fungicide.

Tropical and Subtropical Plants

● Almost all of these are now awake and growing.

● This is a good month to begin serious plantings of these heat lovers.

● Fertilize now with a general-purpose organic fertilizer. Most tropicals and sub-tropicals have a higher need for trace minerals like iron, zinc, manganese, et cetera. Organic fertilizers generally contain lots of these trace minerals and work especially well in warm soil temperatures.

● The real heat-loving tropicals should be awake and growing well now. These include plumeria, ginger, ixora, and heliconia, among others.

● Watering should be frequent now, but most tropicals and sub-tropicals are particular about quick soil drainage.

Foliage Plants

Ornamental grasses should be growing well in May and starting to look great. There's still a bit of time to get ferns transplanted, and they should be growing well by now, too.

Ornamental Grasses:

● The grasses that you cut to the ground in the winter are looking great now. Another application of a mild organic fertilizer will help them along.

For more information, watch & learn: Low Water Ornamental Grasses with James Maxwell

Ferns:

● This is a good time to plant, re-pot, or transplant ferns. Just keep them well-watered.

● It is still a good time to re-mount and/or divide staghorn ferns that have outgrown their boards or pots.

● Most ferns are now growing well and enjoying the warmer weather.

● Continue fertilizing. Use a mild, organic fertilizer on ferns and alternate periodically with an acid type, especially in high pH soil. For most common varieties, try blood meal alternated every third feeding with cottonseed meal.

● If you haven’t already, consider removing old, dry, or tired-looking fronds all the way to their base. Some varieties, like sword ferns, chain ferns, autumn ferns, rabbit-foot ferns, and other rhizomatous varieties, can be revived by cutting all of their foliage nearly to the soil. New growth will quickly reappear.

● Irrigate most varieties regularly according to weather and the growth of the individual plants.

● Continue fertilizing mounted and containerized staghorn ferns with a mild liquid fertilizer. Fish emulsion is excellent.

● Check for pests. Scale can be a problem on several varieties and often goes undetected. It is often closely associated with ants, which need to be controlled as a part of any treatment program. On other ferns, especially staghorns, check carefully for early signs of spider mites.

Vegetables and Herbs

It’s still planting season in your vegetable garden. Get your warm-season transplants and seed into your herb and vegetable garden this month before the temperatures really start rising.

Vegetables:

● Almost any warm-season vegetable can be planted this month. From transplants or seeds, plant beans, celery, cucumbers, eggplants, lima beans, okra, peppers, squash, and tomatoes. Corn, jicama, melons, pumpkin, and sunflowers are best planted from seed.

● Along the immediate coast, gardeners can keep growing many of the cool-season crops like arugula, lettuce, peas, and members of the cabbage family. However, real heat-loving vegetables like corn, melons, peppers, and pumpkins will need a hot south-facing wall.

● This may be the best month of all for planting the real heat lovers like corn, eggplant, jicama, lima beans, melons, okra, peppers, and pumpkins, now that the soil and night temperatures have warmed.

● Plant giant forms of pumpkin toward the second half of this month for a Halloween harvest. Specifically, these are the huge varieties like ‘Big Max’ and ‘Atlantic Giant.’ Standard types should be planted next month.

● The first two or three weeks of flowers on squash and pumpkins are male flowers and will not set fruit. Don’t worry when these dry up; everything is ok. The female flowers will be along shortly. Better yet, use these male flowers as a tasty garnish in the kitchen.

● Putting in successive plantings of many vegetables a couple of weeks apart will ensure a constant, uninterrupted supply for the kitchen.

● Keep tomato plants trained inside their cages or, alternatively, up stakes or obelisks.

● Potato tubers from those planted last fall may still be ready for harvest.

● Keep planting corn from seed this month. Because corn needs to be cross-pollinated, it must always be grown in clumps or rows. Twelve plants is about the minimum for good pollination, and twenty or more is even better. Plant crops successively every three to four weeks for a continual harvest.

● If planted in small groups, hand-pollinate corn.

● Beets, carrots, chard, radish, and possibly turnips can be planted just about year-round. All but chard are planted from seed only.

● Since most annual vegetables are shallow-rooted and quick growing, feed them regularly with a well-balanced organic fertilizer and keep them well-watered during warm weather.

● Control weeds before they get out of hand.

For more information, watch & learn: Vegetable Gardening with Suzanne Hetrick & Gardening 101: How To Plant and Maintain a Vegepod (Part1)

Herbs:

● This is still a great time to plant basil.

● Many perennial herbs can be planted nearly year-round but are particularly well-suited to spring planting since they thrive during the warm summer months. These include marjoram, oregano, rosemary, sage, thyme, catmint, catnip, chamomile, comfrey, feverfew, lavender, lemon balm, lemongrass, lemon verbena, St. John’s wort, tansy, tarragon, and thyme.

● Plant the annual “summer savory” now in the warm weather. The perennial “winter savory” can also be planted now. However, the flavor of the perennial version is generally considered inferior.

● This is still a good time to rejuvenate certain old or tired herbs by giving them a hard trim. These include chamomile, chives, garlic chives, lemon balm, lemongrass, marjoram, mint, oregano, salad burnet, sorrel, St. John’s wort, thyme, and watercress. All of these can be scalped almost to the soil line and, with fertilizing, will recover quickly. Other herbs, like catmint, catnip, feverfew, lemon verbena, rosemary, rue, sage, and tansy, should be cut a bit higher. Cut lavender only very lightly.

For more information, watch & learn: Unique and Unusual Herb Plants with Sarah Smith

General Gardening Info

There are plenty of things to do in your garden in May, from lawn care and soil care to supporting beneficial bug populations. The tips in this section will help you make sure you’ve got your garden and yard maintenance well-planned for May.

Beneficial Insects:

● Eugenia psyllid (Trioza eugeniae) populations will begin coming under control now by a tiny, stingless, parasitic wasp. Do not spray Eugenias; the wasp will do an adequate job.

● Beneficial insects should be abundant in your garden now and taking care of pests—especially if you planted a few flowers just for them.

● Ladybugs and lacewings can be released again this month. Two or three releases of both ladybugs and lacewings in the spring can significantly reduce many pest populations, possibly eliminating the need for pesticides. This is the last of your spring releases of these beneficials.

● Remember that the population of natural predators and parasites always follows behind that of the pest. If predators are present in your garden, even in small numbers, they will need some time to catch up with the pest. Be patient.

● Giant whitefly is active again, and infestations should be noticeable. Predators and parasites should also be present by now, but remember, they will usually be a month or so behind the whitefly population. Check immature whiteflies carefully for indications of parasites. If none are found in one part of the garden, remove a few leaves from another plant that has been parasitized and place it carefully into the foliage of the non-parasitized plant.

● Flea, grub, and cutworm populations may begin showing up now. You can control them by using various beneficial nematodes. These microscopic worms are applied by mixing them in a watering can and drenching the area, then irrigating it with plain water.

● Trichogramma wasps are very effective parasites of caterpillars. If these pests are usually a problem in your garden, a couple of releases of these beneficials will be worthwhile. Space the releases 30 to 45 days apart.

Pests & Diseases:

● Gophers, rabbits, and ground squirrels may start invading your garden this month. As their hillsides, vacant lots, and wild areas (which are reliant on natural rainfall) dry up, they begin moving into gardens for a steady supply of food to maintain them throughout the long dry summer months.

● May is the first month you might need to worry about caterpillars.

● Rose slugs are starting to show up.

For more information, view: How to Identify & Eliminate Common Garden Pests

Lawns:

● Apply your second and last application of pre-emergent crabgrass control to prevent the germination of crabgrass.

● If needed, de-thatch and aerate lawns like hybrid bermudagrass and St. Augustine this month.

● Remember, cool-season lawns should be mowed about a half-inch higher in the warm months than in the cool months. This is a good month to raise the blade height.

● It’s getting a bit late to attempt to plant new cool-season lawns from seed or sod (like fescue/marathon, ryegrass, bluegrass).

● Continue feeding all lawns this month. Cool-season grasses like fescue, ryegrass, and bluegrass are still growing well. Warm-season grasses like bermudagrass, St. Augustine, and zoysia are also growing quickly in the warming temperatures.

● This is also a great month to plant warm-season lawns (hybrid bermudagrass, St. Augustine, etc.) from sod. Most warm-season grasses do not grow from seed and are best only installed from sod.

Soil Care:

● A thick layer of organic mulch, averaging about two inches, should be maintained on top of the soil just about year-round. Add additional mulch as needed to maintain this level. Applied now, a thick layer of mulch will cool the root systems from hot summer temperatures, reduce irrigations as much as half this summer, reduce weed growth, and improve both soil life and soil quality.

● If you have been considering inoculating your soil with beneficial mycorrhizae, this is still a great month to do it. The soil temperatures are perfect for quick establishment. Inoculation can be done very quickly and easily in established areas by using mycorrhizae “tablets.” In moist soil, poke a hole near the plant with a ½” or ¾” rod or stick. Drop a tablet into the hole and push it down with the stick.

● We do not suggest the use of very high-analysis fertilizers in a garden, especially phosphorus. Examples of fertilizers to avoid are synthetic versions with formulations like 10-55-10, 10-30-10, etc. We don’t even suggest the popular 15-30-15 formula. These formulations will inhibit or even destroy much of the soil life that is so vital to a healthy, sustainable soil biome.

● We also suggest that you not use soil-applied systemic fertilizer/insecticide combinations (especially popular with roses). These are very damaging to soil life.

● Use insecticides only when necessary, and even then, use the least-damaging product available. Many of these products move into the soil and interfere with the invisible soil life.

● If you can, begin a compost pile or purchase a compost bin. Leaves, clippings, kitchen produce scraps, and many other ingredients can be composted and returned to the garden. Home compost is one of the very best ingredients you can add to your soil, and the warm air temperatures of summer will help move the composting process along quickly. The benefits are huge in the areas of disease suppression, increasing beneficial microorganisms, improving soil structure and texture, nutrient retention, and detrimental nematode suppression.

● Be sure that, before you put a plant into the ground, you have considered the soil and are doing all you can to improve it and protect its health.

For more information, view: Fertilizer Tips 1-2-3 with Suzanne Hetrick and How to Prepare Your Soil with Suzanne Hettrick

Water & Irrigation:

● It’s better to water plants deeply and less frequently than to offer a short, light sprinkle each day.

● Automatic timers can be turned back on now.

● Check sprinklers for adjustments, faulty heads, etc.

● Continue adjusting the duration and interval settings of automatic sprinkler systems as the weather dictates.

Places to Visit:

● Gardens that look terrific almost any time of the year include Sherman Library and Gardens (Corona del Mar), The Fullerton Arboretum (Fullerton), Los Angeles Arboretum (Arcadia), Huntington Library, and Botanical Gardens (San Marino), and San Diego Botanical Gardens (Encinitas).

● Rose Hills Memorial Park (Whittier).

● The rose garden at the Huntington Library and Botanical Gardens, especially for David Austin varieties.

● One of the finest Mediterranean gardens anywhere is the Leaning Pine Arboretum in San Luis Obispo, on the campus of San Luis Obispo. Beautifully planned, immaculately maintained, and horticulturally more innovative than any on the west coast, this garden should not be missed. May is the perfect month to check it out.

● The month of May is a good time to visit our moist canyons and oak woodlands to observe our native plants. Good choices might include Hot Springs Canyon, upper Trabuco Canyon, and the area around Blue Jay Campground.

● Richard Nixon Library and Birthplace, Yorba Linda.

● Home garden tours.

● The much anticipated Huntington Library and Botanic Gardens Annual Spring Plant Sales are generally held on a Sunday during the middle of the month (it is open to members only the day prior). Lots of new and hard-to-find plants are usually available at this event. If you are a plant collector, arrive early.

Records, Catalogs, Books, and Organizations:

● This is another great month to be making lots of entries into your garden journal. Make notes now about what is blooming, what you like, what you don’t like, plant combinations, and so on. Especially important are the entries that you will make now that guide your garden activities this fall.

● Continue making notes about your roses—specifically, which are performing well and which are not. Notes on disease tolerance will be useful next winter if you decide to upgrade any plants.

● This is another month of many home garden tours. If you haven’t participated in one of these before, it’s truly one of the most rewarding gardening experiences!