Spring in the garden! Expect flowers. And the weeds. And the chicks. And aphids. I hope you have time this month to inhabit the garden and get in on the action.
PLANTING: Hooray! Tomato time! Transplant tomato, pepper, eggplant, okra and sweet potato plants. Plant seeds or transplant seedlings of summer and winter squash (wait until May for pumpkins), cucumber and melon. Towards the end of the month, plant beans and corn seeds. At the start of the month, you can still plant radishes, greens and onions, but be prepared to harvest them while they are young; they will flower quickly in the longer days and warmer temperatures.
You can still transplant almost any ornamental tree, shrub, perennial, and groundcover this month. Plant annuals like zinnias, marigolds and petunias in containers or where you can water them regularly without overwatering the rest of the garden.
MAINTENANCE: Prune flowering shrubs when they finish flowering: azaleas, camellias, forsythias, lilacs, ceanothus, native sage and flowering quince are some examples. Cut citrus fruits and avocado if necessary. You can continue to prune hardwoods if you haven’t already; this may slow growth a bit but will not harm them. Stone fruits ruthlessly thin while the fruit is still tiny, about six to eight inches apart. Mow lawns to three inches in height. Mowing lawns that are too short promotes weeds and disease.
Watch for common spring pests like aphids, earwigs, slugs, snails, whiteflies, thrips and codling moth. Hand picking or spraying with a strong stream of water is the least toxic option. If you must use pesticides, first identify your pest. Many beneficial insects have been killed because of the rush to destroy all insect life in the garden. Some common beneficials that are often mistaken for pests are lacewings, hoverflies, spiders, parasitic mites, and parasitic wasps. Read more on: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74140.html.
Fertilize acid-loving plants (azalea, camellia, gardenia, blueberry) with a specialized fertilizer. There are also specialized fertilizers for lawns, citrus fruits and roses. These special fertilizers contain the necessary trace elements in addition to the big three (nitrogen, phosphorus, potassium). April is also a good month to fertilize fruit and nut trees and potted plants. Avoid over-fertilizing. If in doubt, go a little lighter/weaker than the package instructions. Don’t assume that all weak or struggling plants need fertilizer. It’s best to determine the cause of the symptoms to avoid harming your diseased plant through stress – and adding fertilizer is a stressor.
Powdery mildew is a common disease problem in the spring. The first symptoms appear on the leaves as yellowish spots on the upper surface of the leaves, followed soon after by a fuzzy white powdery substance on the undersides of the leaves. Several types of fungi cause powdery mildew and affect many plants, including grapes and roses. Manage it by growing resistant plant varieties and modifying the growing environment, such as increasing air circulation by pruning and providing more sun to affected plants, even in some cases by transplanting them. Fungicide treatments may be necessary for susceptible plant species, but cultural practices are more effective. Learn more about: http://ipm.ucanr.edu/QT/powderymildewcard.html.
And then there are the weeds. Remove as many as you can, or at least prevent weeds from going to seed by cutting off the tops. Monitor and set bait for ants, which are particularly fond of spurge and spotted spurge. Remember to change the ingredients (which are different from the brand name) of your ant baits every few months.
KEEP: A healthy garden is an active garden. Tolerates some caterpillar damage to healthy ornamentals to support moths and butterflies. Consider sharing the garden with insects of all kinds. Determine a common pest management threshold so you don’t have to feel like you have to eliminate every insect, every weed. You can have a healthy, vibrant garden producing food and flowers, even with a few insects or weeds. Train yourself in the practice of Integrated Pest Management (IPM). The first guideline is Least toxic first. You can move up the toxicity scale as needed to control pests. Conservation doesn’t mean you give up/give up, never spray again. It means being thoughtful and educated about which method to use and when. Don’t be discouraged if you are a new gardener. Gardening is a partnership between humans, insects, birds, weather, plants, mammals and soil microorganisms. Thinking of gardening alone? The Master Gardeners are also here to help, as is the entire online UC IPM program, backed by hundreds of researchers.
As always, conservation means efficiently irrigating the landscape and the food garden. Check for leaks and fix them. Set irrigation controllers. Avoid runoff and excessive watering. Consider adding a rain garden or simple swale to capture more water near your plant roots.
Finally, enjoy the season. Perhaps a walk with wildflowers or other natural areas is possible? Perhaps your own garden is full of vigor and beauty? Happy April!