In most ways gardening is a local topic. Hence, the reason for the Coastal Gardener column. Unknowingly, gardeners receive a great deal of information in a generalized format. When gardening information is heard or read and then re-printed, re-stated, re-distributed and re-read or re-heard, over time it becomes fact. Without really noticing, I suspect most gardeners have absorbed a great deal of their gardening know how from national magazines, television shows, websites, nationally syndicated newspaper articles and gardening books. This knowledge is reinforced by the information written onto the labels of the plants and garden products sold at garden centers.
Take, for example, the addition of pea gravel, rocks, sand or clay chips to the bottom of a container before planting as a way to improve drainage and prevent soggy roots. Sounds logical; water drains quickly through gravel or sand. Standard information, right? It’s been written and re-written in gardening books for decades and you’ll find hundreds of references to this practice on a myriad of websites. Unfortunately, it’s bad information. An urban gardening myth.
A layer of sand, gravel or rock in the bottom of a pot will slow-down water. It will make the pot more soggy and it’s very easy to prove. But the practice still persists. Rocks in the bottoms of pots is a myth, not true. Nonetheless, there is a contingent of gardeners that will stubbornly argue the rocks-in-pots theory. It’s been written, read, said and done so often it must be true.
As we enter the month of September I thought I’d share a few other urban gardening myths, at least in our neighborhood. Some of these have year-round status and others are strictly September myths. If any of these conflict with what you “know” is correct, beware of where you got your information.
During September Don’t:
- Prune hydrangeas. Except for a very unique variety named ‘Endless Summer’, hydrangeas should not be pruned again until after next summer’s bloom. Pruning now means no flowers next year.
- Fertilize camellias. Camellias are entering their dormant period and will not grow again until after next years flowering is complete. Over-fertilizing in the fall and winter is a primary cause of camellia bud drop.
- Plant pansies, violas, snapdragons, cyclamen, primrose and other cool-season flowers. Yes, garden centers and mass merchants have begun stocking cool-season flowers, but it’s too early. Wait another month.
- Plant most bulbs. Nurseries and home stores will have a full selection of daffodils, tulips, ranunculus, freesias, anemones and other bulbs on display. Yes, make your purchases right away, while the selection is at its best, but wait until November or even December to set most of these into the garden.
- Plant California native plants. November or December would be much better.
- Plant basil. This popular herb is a summer annual. In another month or two it’s done.
- Prune pines or eucalyptus. Pines and Eucalyptus, when pruned during the summer months are an easy target for wood boring beetles. Once these troublesome pests attack these trees it is nearly impossible to control them.
- Plant warm season vegetables. It’s too late for peppers, squash, cucumbers, melons, corn and eggplant. Exceptions are a fall crop of bush beans and tomatoes, if you plant right away.
- Plant cool season vegetables. Unfortunately it’s also too early for most of these. Next month would be a better time for transplants like lettuce, cabbage, broccoli, Brussels sprouts, carrots, cauliflower, celery, kale, peas and spinach.
- Apply fertilizers with systemic insecticides included. These insecticides are bad for soil life, bad for the plant and bad for the environment. Regardless, soil applied insecticides are a very inefficient way to control a leaf-feeding pest.
- Cultivate the surface of the soil. This will cause lots of hate mail, but there is no point to this outdated activity.
- Dig in fertilizers. Unless you garden on a 30 degree incline, there is no reason to dig in fertilizers after applying them, regardless of what the label tells you.
During September Do:
- Hose off the foliage of roses frequently. Don’t be duped by the urban myth that wet rose foliage causes powdery mildew. The truth is just the opposite and rinsing the foliage also reduces the likelihood of spider mites and other pests.
- Plant bearded iris. It’s also time to divide established clumps if you haven’t done so in the last three or four years.
- Plant young transplants of most foxglove (Digitalis), delphiniums, hollyhock (Alcea), Canterbury bells (Campanula medium) and Queen Anne’s lace (Ammi majus). In other climates these are planted in spring, but not here.
- Plant sweet peas from seed. September is the beginning of the planting season in mild southern California.
- Begin a compost pile or start a compost bin. Lot’s off fall leaves will be available shortly to get you off to a good start.
Keep reading. Over the weeks and months to come this column will attempt to keep bringing you accurate, local gardening information that will help you have a successful and enjoyable garden; and we’ll probably uncover a few more urban myths along the way.
Ron Vanderhoff is the Nursery Manager at Roger’s Gardens, Corona del Mar