May Gardening Calendar

Ornamentals

• Pinch azaleas and rhododendron blossoms as they fade. Double flowered azaleas need no pinching.
• Fertilize azaleas after bloom. Use a formulation which has an acid reaction.
• If spring rains have been sparse, begin irrigating, especially plants growing in full sun.
• Apples, crabapples and hawthorns susceptible to rust disease should have protective fungicidal sprays applied beginning when these trees bloom.
• Weeks 1-2: Don’t remove spring bulb foliage prematurely or next year’s flower production will decline.
• Weeks 1-2: Canker worms (inch worms) rarely cause permanent damage to ornamentals. Use B.T. if control is deemed necessary.
• Week 1: Begin planting gladiolus bulbs as the ground warms. Continue at 2 week intervals

Vegetables

• Growing lettuce under screening materials will slow bolting and extend harvests into hot weather.
• Slugs will hide during the daytime beneath a board placed over damp ground. Check each morning and destroy any slugs that have gathered on the underside of the board.
• Place cutworm collars around young transplants. Collars are easily made from cardboard strips.
• Weeks 1-2: Plant dill to use when making pickles.
• Week 1: Thin plantings of carrots and beets to avoid overcrowding.
• Week 1: Keep asparagus harvested for continued spear production. Control asparagus beetles as needed.
• Weeks 3-4: Set out peppers and eggplants after soils have warmed. Plant sweet potatoes now.

Fruits

• Mulch blueberries with pine needles or sawdust.
• Week 1: Don’t spray any fruits while in bloom. Refer to local Extension publications for fruit spray schedule.
• Week 4: Prune unwanted shoots as they appear on fruit trees.

Lawns/Turfgrass

• Keep bluegrass cut at 1.5 to 2.5 inch height. Mow tall fescue at 2 to 3.5 inch height.
• Weeks 2-4: Mow zoysia lawns at 1.5 inch height. Remove no more than one-half inch at each mowing.
• Weeks 2-4: Apply post-emergence broadleaf weed controls now if needed.
• Weeks 3-4: Zoysia lawns may be fertilized now. Apply no more than 1 pound of actual nitrogen per 1000 square feet.
• Week 4: Watch for sod webworms emerging now.

Miscellaneous

• Birds eat many insect pests. Attract them to your garden by providing good nesting habitats.
• Weeks 2-4: Herbs planted in average soils need no extra fertilizer. Too much may reduce flavor and pungency at harvest.
• Weeks 3-4: Sink houseplants up to their rims in soil or mulch to conserve moisture. Fertilize regularly.
• Weeks 3-4: Watch for fireflies on warm nights. Both adults and larvae are important predators. Collecting may reduce this benefit.