Ask an Expert: Monthly Checklist from USU Extension Gardener's Almanac

April showers bring May flowers – as well as a wide array of gardening tasks. Utah State University Extension’s Gardener’s Almanac provides a checklist for each month as well as links for tips and further information.

The May checklist follows:

• Plant warm-season vegetables and annual flowers once the threat of the last frost has passed. Click here for a listing of the average last and first frost dates.
• By planting tomatoes deeper, they are able to form more roots along the stem, creating a more vigorous plant.
• Consider planting sweet corn in the garden every other week (until early July) to extend the harvest.
• Consider the various types of fertilizers. Click here for information on traditional fertilizer options. Click here for information on organic fertilizers.
• Thin out overcrowded seedlings using a pair of scissors. Try to avoid disturbing the young roots.
• Protect fruit blossoms and tender garden plants from late freezing temperatures. Click here for information on critical temperatures and fruit.
• Plant summer-blooming bulbs including gladiola, begonia, dahlia and canna.
• Divide warm-season ornamental grasses when new growth begins to emerge.
• It’s already time to take notice of weeds. Click here for information.
• Allow the foliage of spring blooming bulbs (tulips, daffodils and crocus) to die down before cutting the leaves off.
• Click here for information on planting a lawn.
• Turfgrass needs minimal irrigation each week. Click here to learn about irrigation needs in your area.
• In compacted sites, aerate with hollow core aerator when turfgrass is actively growing (April to June).
• Control broadleaf weeds in the lawn when temperatures are between 60 and 80 F. Follow the label and stop use of broadleaf herbicides once the temperature is above 85 F.
• Apply a slow-release lawn fertilizer to provide a long-lasting effect throughout the summer months.

Pests and Problems:

• Monitor newly planted vegetables for cutworm and flea beetle damage.Monitor for cankerworm damage on scrub oak and Box Elder trees along the foothills.
• Monitor for aphids on lush new spring growth on a variety of plants. Treat for aphids by using “softer” solutions such as spraying them with a hard stream of water or by using an insecticidal soap.
• Monitor for slugs and snails. These pests thrive in moist, cool areas of the garden and landscape, feeding on a variety of plant hosts.
• Protect Ash trees from the lilac-ash borer around the first of May
• Control codling moth in apples and pears to reduce wormy fruit. For specific timing, see the Utah Pests Advisories.
• Treat for powdery mildew on apples beginning when leaves are emerging (at ½-inch green) until June.
• Watch for insect pests in raspberries from mid-May thru early June.
• Watch for cutworm damage in turfgrass and new vegetable starts.
• Monitor for damaging turfgrass insects. In areas previously damaged, consider a preventative (systemic) insecticide.

For all things gardening, visit garden.usu.edu. Here you will find videos, checklists, downloadable information, information on our demonstration gardens, and sign-up links for our online gardening courses.