from the Extension Master Gardener Volunteers

The estimated last frost date in Transylvania County is May 10^th, which is when it is safe to begin putting out tender plants. Tender plants include annual flowers, vegetables such as tomatoes, peppers and squash and houseplants.

It is also a very busy month, as now is the time to get your gardening tasks accomplished to ensure a smooth growing season and beat the heat.

Fertilizing

• Fertilize summer flowering shrubs such as crape myrtle and rose-of-Sharon with one cup of 10-10-10 per plant. Fertilizing trees and shrubs
• Side-dress or fertilize your vegetables six to eight weeks after germination.
• Fertilize new plantings with one pound of 10-10-10 per 100 ft² if you have not done a soil test. Fertilizing vegetable beds
• Fertilize grape vines, blackberries, raspberries and blueberries. Fertilizing small fruits

Planting (last estimated frost date is May 10^th)

• Plant containerized and balled and burlap shrubs, perennials and ground cover plants. Planting trees and shrubs
• Plant gladioli, canna, dahlias, lilies and other summer flowering corms and bulbs this month. Summer-flowering bulbs
• Plant tender summer annuals such as begonia, geranium, marigold, petunia and zinnia this month after danger of frost or where they can be covered if frost threatens. Annual flowers
• The following vegetable plants can be set out this month: broccoli, Brussels sprouts, cabbage, eggplant, pepper, tomato and sweet potato after danger of frost or where they can be covered if frost threatens. A Beginner’s Guide to Vegetable Gardening
• The following vegetable seeds can be direct planted this month: bush, pole and lima beans, beets, broccoli, Brussels sprouts, cabbage, cantaloupe, corn, cucumbers, lettuce, okra, southern peas, radishes, pumpkin, summer and winter squash, Swiss chard and watermelon.

Pruning

• Prune hybrid Rhododendron after blooms fade. Always prune to a whorl of leaves or to the next branch. Pruning trees and shrubs
• Limit growth and encourage fullness of fast growing evergreens by pinching off half of the length of the “candles” or new growth at the tips of branches. Pinching
• Prune hedges including abelia, holly, euonymus, boxwood, etc., as desired. Always make the top of the hedge narrower than the bottom to allow sunlight to reach the lower branches.
• Begin pinching your chrysanthemums and continue through early July.
• Pinch zinnia, salvia, celosia, petunias, marigolds and snapdragons to slow top growth and encourage branching and more blooms.
• Pick off azalea leaf galls as they form. Do not compost, throw in the trash. Azalea Leaf Galls
• Do NOT cut back spring bulb foliage until it turns yellow and brown.

Managing Pests and Diseases

• If needed, spray iris beds for borers. Iris borers
• Continue rose spray program. Fungus on roses
• Continue spraying your fruit trees and bunch grapes according to the fungicide program. Fruit Spray Schedule.
• Monitor vegetables for insects and diseases, spray as needed. Vegetable disease control and Vegetable pest control
• Spray your squash plants near the base of the stem to control squash borer. Continue through June 1st and use only the recommended insecticide. Squash vine borer control
• Monitor for insects and if needed, spray the following landscape shrubs for the following insect pests: Arborvitae (bag worm), azalea (lace bug), boxwood (leaf miner), euonymus (scale), hemlock and juniper (spruce mites, aphids), pyracantha (lace bug and hybrid rhododendron borer). Scouting for insect damage
• Use pesticides sparingly. Spray/treat only when needed.

Lawn Care Lawn care information

• Fertilize zoysia this month after it has greened up. Do NOT fertilize tall fescue now.
• Start warm season lawns.
• Mowing heights for your lawn are important. Cut tall fescue and bluegrass at 3 inches, zoysia at 1 inch.
• Apply broadleaf herbicide as needed.
• Apply insecticide for grub control as needed.
• Apply 1” of water per week if you seeded your lawn this spring.

Propagating

• Take softwood cuttings of plants such as azalea, rhododendron, forsythia, clematis, geranium and chrysanthemum in late May. Propagation from cuttings

Miscellaneous To Do

• Move houseplants outside if desired when all danger of frost has passed. Moving houseplants outside
• If weather has been dry, give favorite plants a good soaking once a week. Design and plant window boxes and container gardens Container gardens
• Put out hummingbird feeders.

Plants in Bloom in May: Southern Magnolia, Golden Chain Tree, Kousa Dogwood, Viburnum, Hybrid Rhododendron, Mountain Laurel, Satsuki Azalea, Scotch Broom, Deutzia, Beauty Bush, Weigela, Gumpo Azalea, Roses, Clematis, Honeysuckle, Dianthus, Sweet William, Candytuft, Bearded Iris, Peony, Coreopsis, Poppy, Lady Slipper, Summer Annuals