Dare we believe that spring is here? 2023 is shaping up to be a year of super blooms. If you can, take a drive to see some of the wildflowers, but be careful because roadways may remain flooded all month and new roadways may flood. In our gardens, too, we should see foliage growth and flowers. This is a month of plenty of activity and plenty of chances to be outside enjoying and working in our gardens.
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.
We’ve had a late start on spring transplanting because of the weather, but we can catch up in April. You can plant almost any ornamental tree, shrub, perennial, and ground cover this month, including citrus and avocado. Annuals for summer flowers to plant include zinnia, sunflower, marigold, and petunia. Don’t be too quick to remove stock and snapdragon; many of the newer varieties withstand the heat better than their ancestors.
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 about biological controls for insect pests at tinyurl.com/4insectpests.
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. But be aware of 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 by stressing your unwell plant. 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/4mildew.
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. Hand pulling weeds with a favorite beverage nearby can be great garden therapy.
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 feel pressured to eliminate all insects, all weeds. You can have a healthy, vibrant, food and flower-producing garden even with a few pests. Healthy insects means healthy food for birds. Train yourself to practice Integrated Pest Management (IPM). The first guideline is Least Toxic First. Conservation doesn’t mean you give in/give up, never spray again. It means being educated on what method to use and when. Don’t get discouraged if you’re a new gardener. Gardening is a 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 even in a non-drought year. Look for leaks and repair them. Adjust irrigation controllers. Avoid run off and over watering. Consider adding a rain garden or simple swale to keep storm water on your property. Even urban gardens can have a small retention basin.
Enjoy the month of sunshine, vigorous garden life and, yes, even a few storms.
The Master Gardeners will be live to answer your questions on Saturday, April 8, 8 to 11 a.m. at Visalia’s Farmer’s Market in Sequoia Mall’s southwest parking lot. You can also contact them at 559-684-3325, or visit their web site at ucanr.edu/sites/UC_Master_Gardeners.