Gardening Tips for May

By Peyton Ellas
UCCE Master Gardener

Have you been spending more time in the garden this spring? It seems like everyone is rediscovering vegetable gardening and getting those ornamental planting beds renovated. Even just buying some flowering perennials can liven up our gardens and give our spirits both a lift and a bit of calm. While gardening is a great idea, remember to wear those face masks and keep six feet apart when going to public shops. I have been digging through my years of saved seeds and finally getting them planted. And weeding. Lots of weeding. Both of those are projects I can do without leaving the house and are immensely satisfying. I’ve also reclaimed old wood and metal to make garden signs and other art. What home garden projects have you been finally getting to this spring? Here are some ideas: 

Planting: Finish up spring planting in the ornamental garden before hot weather arrives. Almost everything can be planted now, especially early in the month. Bulbs, tubers and corms to plant are dahlia, gladiolus and tuberose. Succulents are fine to plant now too, as are avocados, citrus, bougainvillea, and other heat lovers. Vegetables to plant now include tomatoes, peppers, basil, eggplant, summer squash and tomatillos. These heat-lovers do best in six-to-eight hours of sun a day. Don’t worry about some shade in your garden. In the Central Valley and low foothills, some shade is actually a good thing. Heat lovers that can take more full sun are winter squash, melon, okra, beans and corn. 

Maintaining: Check your watering system and get ready to adjust as the weather warms. Your new transplants will need to be supplied with water on a regular basis through late spring and right into summer. Don’t expect even low-water-use plants to survive on no water during their first year at least. Deep water stone fruit, apple, pear and nut trees.

Prune spring-blooming shrubs as they finish flowering. Pinch back fall-blooming chrysanthemums until July. Deadhead roses (remove old flowers) to encourage repeat blooming. Trim off suckers from the base of roses and from trees, and take out any dead branches now that trees are fully leafed out. Thin your nut and stone-fruit trees when the fruit are small to improve fruit size and quality. How much will you realistically consume? Thin, and then wait a day or two and then thin some more. Branches may break and fruit size will be smaller if a tree is overloaded with fruit. For young trees (less than five years old), allow only a few fruits to grow to maturity so the tree can put more energy in root and shoot growth. Cage young trees against ground squirrels and deer in the foothills and mountains. 

Continue with weeding. 

Top dress with compost and/or mulch if you haven’t already. Bare dirt is not healthy for plants. Whether rock, gravel or organic (bark or leaves), mulch is part of a healthy, modern garden. Even around fruit trees, you can safely leave a shallow layer of mulch or, better, top dress with compost. Keep all organic mulch at least six inches away from tree trunks and woody crowns. Woody crowns appear on a wide variety of our favorite low-water shrubs like most sage, rosemary, lavender, rockrose, manzanita, California lilac and coffeeberry. 

We have a lot to think about, but this year too, we will need to monitor our landscape water use to avoid adding too much. The top inch or so of soil should dry out between watering cycles. For established gardens, the top several inches can dry out for almost all plants in the well-mulched garden. Many people overwater their lawns, especially in late spring. This encourages disease and insect problems. Also, raise the mower height to shade out weeds. 

Insect pests can attack the edible garden during warm weather, so regular observation and quick action are called for. Earwigs, aphids, slugs, snails and grasshoppers started to appear in April. Blast soft-bodied insects like aphids with a stream of water. Insecticidal soap is a good all-purpose insecticide for many insects, and it doesn’t kill as many beneficial insects as broad-spectrum powders and sprays do. Try to tolerate some damage in order to feed garden friends like birds, spiders, lacewings, ladybugs, assassin bugs, lizards and praying mantis. Hand pick tomato/tobacco worms, hoplia beetles on roses, snails and slugs. Root cage and cover gardens to exclude rodents. Leave rolled newspaper traps or put a little oil into opaque bottles and leave them laying sideways under garden plants to trap earwigs and other beetles. The traps need to be put in the waste every morning until the population is diminished. Control scale (they appear as little bumps on stems of citrus, bay, and other plants) with summer horticultural oil. You may need to repeat application in June. Follow package instructions to avoid harming your plants. 

Fertilize your container plants now. Once a year is usually enough for most containers. Once every three years may be all that is needed for California native plant containers. You may never need to fertilize your succulent and cactus. Fertilize azaleas, camellias, and gardenias with fertilizer labeled for them. Fertilize citrus with fertilizer labeled for them. Citrus in containers need to be fertilized at least once a month during their blooming and growing season. They’ll live without it, but may not produce much, if any, fruit. Citrus in the ground should be fertilized this month and then not again until next year. Fertilize your warm-season lawn and ground-covers with an all-purpose product to promote vigorous growth and help prevent weeds. If you haven’t already, fertilize your roses.

Conserving: Don’t disturb your bee nesting and bird houses. Observe your trees before having the tree trimmers come to make sure you’re not disturbing an active bird nest. Leave a little radish, mustard and broccoli blooming in the edible garden until seed-set to support pollinator insects. Consider adding a new plant for the wildlife. Do you have room for a quailbush, mulefat or California fuchsia? Do you have room for yarrow, California buckwheat or native milkweed (these have pink and white flowers, not yellow or orange flowers)? Can you dedicate a space in the garden that is less manicured? This will support the greatest diversity and number of native bees, beneficial insects, lizards, toads and birds. 

Lounge in a comfy chair near all the wild spring activity. This is one event we can all attend, right in our own gardens.

Due to the shelter-at-home guidelines, the Master Gardeners have canceled all public events until at least May 10, but their phone lines are still open: 559-684-3325, Tuesdays and Thursdays between 9:30 and 11:30 a.m.

Start typing and press Enter to search