Apr 3, 2024
Spring is here and if you are like us, you can't wait to get outside and see how your plants and garden are doing! As usual, UC IPM has useful tips for the month of April to prevent pests in the garden and landscape. To see more tips specific to your region, visit the Seasonal Landscape IPM Checklist on the UC IPM website. Here are some general tips to get you started:
- Cover fruit trees with netting to exclude birds and other vertebrate pests.
- Aphids are out already so look for them and their natural enemies such as predaceous bugs like lacewings, lady beetles, and syrphid flies. On sturdy plants, spray aphids off with a strong stream of water or apply insecticidal oils or insecticidal soaps to kill them.
- Manage ants. Plants infested with honeydew producing insects like aphids, whiteflies, and mealybugs may attract ants who take that honeydew back to the nest to feed the colony. Manage ants around landscape and building foundations using insecticide baits and trunk barriers.
- Whitewash tree trunks to deter borers and prevent sunburn. Apply to young trees or older bark on susceptible trees newly exposed to sunlight.
- Look for signs of clearwing moths boring in ash, birch, pine, poplar, and willow.
- Check for signs of powdery mildew on apple, crape myrtle, grape, rose, and stone fruits. Take preventative measures, like pruning, to provide better air circulation between plants.
- Watch for yellowjackets and other wasps building nests in undesirable locations. Knock down newly started nests and use lure or water traps to control populations.
- Prevent mosquitoes by eliminating standing water in gutters, drain pipes, flowerpots, etc. Place Bt “dunks” (Bacillus thuringiensis subspecies israelensis) in birdbaths and ponds to selectively kill mosquito larvae.
- Adjust watering practices as rainfall decreases. Check irrigation systems for leaks and broken emitters and perform maintenance as needed. Consider upgrading the irrigation system to improve its water efficiency.
- Monitor stone fruit trees for pests such as aphids, borers, brown rot, caterpillars, powdery mildew, and scale insects.
Don't see your county on the checklist or want to provide feedback? Let us know!
