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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 and strawberries
  • Kiwis (give ? of recommended annual NPK, ? in May)
  • 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 (209) 223-6838.
  • 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) - for apple scab, 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.