TULSA MASTER GARDENERS

May

Gardening Tasks Reminder

By Shirley Miller, Master Gardener

F ertilize

Apply an application of fertilizer to cool season turf grass. Use a nitrogen fertilizer (33-0-0 or 46-0-0. Refer to Fescue/Rye Grass Maintenance, also available at the Tulsa County Extension Center. May is time to fertilize warm season grasses. Apply 1 pound actual nitrogen per 1000 square feet at each application. Use a complete N-P-K fertilizer in a 3-1-2 ratio (21-7-14, 24-8-16) for the mid-May and September applications. Use nitrogen only fertilizer in July.

Feed Azaleas after bloom is complete. Use a fertilizer especially formulated for azaleas and other acid loving plants.

Fertilize Roses according to package directions. Remember to place fertilizer in a small circle around, but not touching the stems. Scratch in lightly and water.

Fertilize annuals 7 to 10 days after transplant and monthly thereafter. If you choose a slow release fertilizer, follow package directions.

W ater

May is usually a wet month in our area. However, if we fall behind on rain, get out the sprinkler. General rule: apply 1 inch of water per week Keep newly planted seeds moist. Watch newly planted seedlings carefully. Wilt due to lack of water will significantly inhibit growth. Newly planted trees and shrubs need to be watered diligently to encourage strong roots before summer heat. Always water in fertilizer shortly after applying. Fertilizer and herbicides degrade in sunlight.

M ulch

After spring rains, wait until soil begins to dry out before using mulch.

P rune

Prune climbing roses after they finish blooming. Remove dead or damaged canes and remove large, old canes at the ground level. Refer to OSU Fact Sheet 6403, "Rose Culture in Oklahoma".
Roses in the Landscape

Prune spring flowering shrubs after they bloom. Azaleas can be pruned after they flower. Refer to OSU Fact Sheet 6409,
Pruning Ornamental Trees and Shrubs.

Divide daylily clumps for better bloom and more plants.
Do not remove foliage from spring flowering bulbs. Allow to die back naturally. Dead wood can be removed from crepe myrtle.
Deadheading, or removal of spent blossoms allows a plant to spend it's strength on more blossom rather than making seed.
Trim back creeping phlox.

P lant

Annual bedding plants can be set out for summer color.
Plant summer bulbs such as cannas, dahlia, elephant ear and gladiola.
Plant watermelon, cantaloupe, cucumber, eggplant, okra, sweet potatoes, etc.
Wait until the soil warms up to plant zinnias, periwinkle and other heat loving flowers. By mid-month, the soil will be warm enough to plant Caladium.

P ests

Aphids populations begin in May. Early treatment will help keep down numbers. For best control spray when you first see aphids and repeat in 10 days. A strong spray of water from the hose will often suffice. Other insects to watch for: Bagworms on juniper and arborvitae. (Late May). Elm leaf beetles and larvae on elms (Late May). Mimosa webworms on mimosa and honeylocust. Lace bugs on sycamore, pyracantha and azalea. For information on control of these and other pests, call the Master Gardener office, Phone 746-3701, Monday thru Friday, 9am to 4 pm.

Post emergent treatment for nutsedge are best applied this month. Make sure warm season grasses have completed greening up. Refer to OSU Fact Sheet 6421,
Controlling Weeds in Home Lawns
To determine if you have spider mites, shake a leaf over white paper. If tiny specks begin to crawl, mites are present. Here again, a strong spray of water from the hose can suffice as control.

Tips

1. Poison ivy leaves stems, berries and roots all contain an oil that can irritate sensitive skins any time of the year. Round-up herbicide is one of the most effective chemicals for control. Try to avoid getting this non-selective herbicide on nearby desirable plants. Poison ivy is a woody plant and may require more than one treatment.
2. Proper cutting of roses, both for indoor bouquets and to trim faded flowers makes a better looking plant and good follow up bloom. If possible, make all cuts just above an outward facing bud. Always leave at least two sets of five leaves when cutting.
3. If you plan to put indoor plants out for the summer, remember to let the plants harden off. Place the plants in a protected place in shade for just a few hours, gradually increasing outdoor time. Sun and wind will make the plant require more water and fertilizer.
4. Set your lawn mower height at 1 1/2 inches for warm season grasses and 2 inches for cool season grasses.
5. Clean out water gardens and prepare for season. Divide and repot water garden plants. Begin feeding fish when water temperatures are over 50 degrees.
6. Stay out of the garden when it's wet to prevent disease spread from plant to plant.
7. If you pull out maple and elm seedlings now, you won't have to dig them out later.
8. Slugs will avoid spiny, spiky materials. Finally we've found a use for sweet gum balls! Make a tight circle of the balls and place around tender plants.
9. May is such a busy time in the garden, what with all the cleaning, preparing beds, planting, weeding, seeding, etc. Don't forget to take time to enjoy the lovely results of your hard work together with our usually beautiful weather.

Master Gardeners are ready to answer your horticulture questions. Call 746-3701 at the Extension Center 9 to 4, Monday thru Friday. Master Gardeners also answer the phone at the Tulsa Garden Center 9 to 12, Monday thru Friday.

Shirley can be reached by Email: SHIRLEY.