April Gardening Tips

Garden Maintenance

• 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 fire blight; 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 grafting.
• Control slugs, snails and earwigs with traps or barriers.
• Thoroughly clean debris from ponds, fountains and bird baths.
• Remove ladder fuels on your property that can increase how fast fire spreads.
• Check dates of Master Gardener classes.

Fertilize

• 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.
• Citrus are heavy nitrogen feeders. Mature trees need 1 ½ lbs. N per year.
• 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 fire blight.
• 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

Plant Seed

• 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

• Gladiolus.
• Below 2000 ft.: parsley, peppers, strawberries, melons, squash tomatoes, citrus, dahlias.
• Above 2000 ft.: cabbage family, parsley, strawberries.

Flowers

• 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.

Vegetables

• 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.

Lawns

• Seed and renovate lawns.

Trees and Shrubs

• Last chance for planting citrus trees.
• Weather permitting, frost-tender plants can go outside now.