- Pinch chrysanthemums back to 6 inches every month through July.
- Trim dead flowers but not leaves, from spring bulbs.
- Mulch cane berries, cut out all old canes and reset new canes in twine.
- Cultivate and pull weed seedling now to prevent bloom.
- Check irrigation system and perform maintenance as needed.
- Check hoses as needed for fire protection.
- Prune apples, pears, any shoot tips with powdery mildew or fireblight; azaleas, rhododendrons, flowering fruit trees after bloom if needed, spring flowering shrubs, frost-damaged growth.
- Mow or cultivate grass around orchards to discourage thrips and plant bugs.
- Best time for cleft graphing.
- Control slugs, snails and earwigs with traps or barriers.
- Thoroughly clean debris from ponds, fountains and bird baths.
- Check dates of Master Gardener classes.
- Deciduous fruit trees and young shade trees at first leaves if not done in March.\
- Azaleas, rhododendrons after flowering.
- Apply chelated iron to azaleas, gardenias and camellias if leaves are yellowing between the veins.
- Cool season turf grass
- Cane berries, strawberries.
- Kiwis (give ? of recommended annual NPK, ? in May).
- Citrus are heavy nitrogen feeders. Mature trees need 1 ½ lbs. N per yea
- Divide this amount by 4 and apply each quarter one month apart for 4 months, beginning in March.
- Fertilize shrubs and trees once during spring with slow-release fertilizer.
- Fertilize bulbs after bloom.
Spray: Check the California Backyard Orchard website for current information.
- Set codling moth traps to indicate timing of sprays. Call Master Gardeners for more accurate timing (530) 621-5512.
- Pears, except Comice – weak copper spray when in bloom, one to three applications for fireblight.
- Stone fruit (below 2000 ft) – If rainy. Wet weathers favors brown rot.
- Stone fruit (above 2000ft.) - fixed copper when buds are swollen and starting to
- show first color to control brown rot, peach leaf curl, pseudomonas, blossom and canker infections.
- Grapes – treat with sulfur or other fungicide when shoots are 2” to 6” long.
- Continue every 7-10 days until fruit start to color.
- Apples (above 2000 ft) - when apple buds first show signs of green and repeat spray every 10 days until bloom where scab is a problem. In many cases this treatment may be combined with February insect controls.
- Check roses for black spot, mildew and rust and spray if needed.
- Check roses for aphids; control with a strong spray of water or insecticidal soap.
What To Plant In April
- Beets carrots, Chinese cabbage, lettuce, radish, turnips.
Below 2000 ft: corn, lima beans, melons, potatoes, pumpkins, snap beans, summer squash, winter squash (marginal – only if weather has warmed).
Marigold, zinnia, sunflower (if weather is warm), alyssum.
Plant Seed - Greenhouse or Cold Frame
- Above 2000 ft: melons, peppers, pumpkins, summer squash, tomatoes. Marigold, zinnia.
Set out Plants
- Below 2000 ft.: parsley, peppers, strawberries, melons, squash tomatoes, citrus, dahlias.
- Above 2000 ft.: cabbage family, parsley, strawberries.
- Last chance to plant pansies, violas and primroses.
- Make a last planting of summer bulbs.
- Set out perennials.
- Many annuals may be seeds at elevations up to 1500 ft.
- Transplant tomatoes, eggplant and peppers as temperatures warm.
- At cooler elevations, transplant lettuce cabbage family, collards and kale.
- After danger of frost, plant cilantro and two week intervals for a steady supply.
- Seed and renovate lawns.
Trees and Shrubs
- Last chance for planting citrus trees.
- Weather permitting, frost-tender plants can go outside now.