Spring in the garden! Expect flowers. And weeds. And baby birds. And aphids. I hope you have time this month to inhabit the garden and get in on the action.
Planting: Hooray! Tomato time! Transplant seedlings of tomatoes, peppers, eggplant, okra, and sweet potatoes. 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 seeds of beans and corn. Early in the month, you can still plant radishes, greens, and onions, but be prepared to harvest them while small; they will go to flower quickly in the lengthening days and warm temperatures.
You can still transplant almost any ornamental tree, shrub, perennial, and ground cover this month. Plant annuals like zinnia, marigold, and petunias in containers or where you can water them regularly without over-watering the rest of the garden.
Maintaining: Prune flowering shrubs when they finish blooming: azaleas, camellias, forsythia, lilacs, ceanothus, native sage and flowering quince are some examples. Prune citrus and avocado if necessary. You can continue to prune deciduous trees if you haven’t yet; it may slow the growth a little but won’t hurt them. Ruthlessly thin stone fruits while the fruit is still tiny, to about six to eight inches apart. Mow lawns to three inches tall. Mowing lawns too short encourages weeds and diseases.
Monitor for common spring pests like aphids, earwigs, slugs, snails, whitefly, thrips, and codling moth worm. Handpicking or spraying with a strong stream of water is the least toxic option. If you must use pesticides, identify your pest first. Many a beneficial insect has been killed because of haste to destroy all insect life in the garden. Some common beneficials that are often mistaken for pests are lacewing, syrphid fly, spiders, parasitic mites, and parasitic wasps. Read more at tinyurl.com/4dc4a6fj.
Fertilize acid-loving plants (azalea, camelia, gardenia, blueberry) with specialized fertilizer. There are also specialized fertilizers for lawns, citrus, and roses. These special fertilizers contain the trace minerals needed in addition to the big three (nitrogen, phosphorus, potassium). April is also a good month to fertilize stone fruit and nut trees and container plants. Avoid over-fertilizing. When in doubt, go a little lighter/weaker than package instructions. Don’t assume all weak or struggling plants require fertilizer. It’s best to determine the cause of the symptoms to avoid harming your unwell plant by stress—and adding fertilizer is a stressor.
Powdery mildew is a common disease problem in spring. Initial symptoms appear on leaves as yellowish spots on the upper leaf surface, followed a short time later by fuzzy white powdery stuff on the bottoms of the leaves. Several fungi types cause powdery mildew, and it affects many plants, including grapes and roses. Manage it by growing resistant plant varieties and altering the growing environment, such as increasing the air circulation by pruning and providing more sunlight to affected plants, even in some cases by transplanting them. Fungicide treatments might be required for susceptible plant species, but the cultural practices are more effective. Learn more at tinyurl.com/yk9kwy4c.
And then there are weeds. Remove as many as you can, or at least prevent weeds from going to seed by chopping off the tops. Monitor and set baits for ants, which especially like spurge and spotted spurge. Remember to change the ingredients (which is different from the brand name) of your ant baits every few months.
Conserving: A healthy garden is an active one. Tolerate some caterpillar damage on ornamental healthy plants to support moths and butterflies. Consider sharing the garden with insects of all sorts. Determine a management threshold for common pests so you don’t have to feel you have to eliminate all insects, all weeds. You can have a healthy, vibrant, food and flower-producing garden even with a few bugs or a few weeds. Train yourself to practice integrated pest management (IPM). The first guideline is least toxic first. You can travel up the toxicity scale as needed to control pests. Conservation doesn’t mean you give in/give up, never spray again. It means being thoughtful and educated on what method to use and when. Don’t get discouraged if you’re a new gardener. Gardening is partnership between humans, insects, birds, weather, plants, mammals, and soil micro-organisms. Did you think you were gardening alone? Master Gardeners are also here to help, as is the entire UC IPM program online, backed up by hundreds of researchers.
As always, conservation means irrigating the landscape and edible garden efficiently. Look for leaks and repair them. Adjust irrigation controllers. Avoid run off and over watering. Consider adding a rain garden or simple swale to capture more water close to your plants’ roots.
Finally, enjoy the season. Perhaps a walk with the wildflowers or other natural areas is possible? Perhaps your own garden is full of vigor and beauty?
The Master Gardeners will be live to answer your questions on Saturday, April 2, 9:30 a.m. to 3:30 p.m. at the Main Street Jamboree at Mooney Grove Park in Visalia; and 10 a.m. to 2 p.m. at the Tulare Garden Festival at Tulare City Public Library. You can also contact them at 559-684-3325, or visit their web site at ucanr.edu/sites/UC_Master_Gardeners.