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

Julene Reese

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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 Here you will find videos, checklists, downloadable information, information on our demonstration gardens, and sign-up links for our online gardening courses.