Helpful Garden Tips for April

The first day of spring is called the vernal equinox, and this year it occurs on March 20. April is usually the month of wildflower bloom and taking a viewing drive. In our gardens, too, we should see foliage growth and flowers. This is a month of garden activity and chances to be outside enjoying and working in our gardens.

Planting

Transplants of most summer vegetables can be planted now, along with seeds of squash, beans, corn, cucumber and melon. 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.

Maintaining

Prune flowering shrubs when they finish blooming: azaleas, camellias, forsythia, lilacs, ceanothus and native California sage like Pozo Blue. 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, take the time to identify your pest insect first to avoid harming beneficial insects like lacewing, syrphid fly, spiders, parasitic mites, parasitic wasps and lady bug larva.

Remember that caterpillars are our future moths and butterflies, which provide food for birds and other creatures, so avoid pesticides unless you have a large population destroying plants. In that case, use a Bt spray (common names include Caterpillar Killer), a highly selective pesticide that only kills caterpillars and is not toxic to their natural enemies.

Fertilize acid-loving plants (azalea, camelia, gardenia and 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 and potassium).

April is also a good month to fertilize stone fruit and nut trees and container plants. Avoid over-fertilizing. When in doubt, use a half-strength mix. Don't assume all weak or struggling plants require fertilizer.

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. Learn more at: http://ipm.ucanr.edu/QT/powderymildewcard.html

And the weeds continue.

Remove as many as you can, or at least remove the seed heads if you can. Avoid bare dirt, which makes erosion issues worse. It's okay to chop weeds down but leave the roots, especially for annual weeds.

Serving

As always, conservation means irrigating the landscape and edible garden efficiently. Look for leaks and repair them. Adjust irrigation controllers. Avoid runoff 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.

A healthy garden is an active one. Consider sharing the garden with insects. Determine a management threshold for common pests so you don't feel pressured to eliminate all insects or all weeds. You can have a healthy, vibrant, food and flower-producing garden even with a few pests. Healthy insects mean healthy food for birds.

Train yourself to practice Integrated Pest Management (IPM). Conservation doesn't mean you give in/give up, never spray again. It means being educated on what method to use and when. The first guideline is Least Toxic First.

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.

Enjoy the month of sunshine, vigorous garden life and, hopefully a few storms.

Happy Gardening!

Questions?

Call the Master Gardeners:

Tulare County: (559) 684-3325, Tuesday and Thursday 9:30-11:30 a.m.

Kings County: (559) 852-2736, Thursday only, 9:30-11:30 a.m.

Visit our website for past articles, sign up for our e-newsletter, or email us with your questions: http://ucanr.edu/sites/UC_Master_Gardeners/

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