The activity in your gardens is about to go up a few notches as the days get longer, warmer and there is still adequate natural rainfall. The lawn will need regular mowing and shrubs pruning. Now that the apple trees have blossomed the odds of a last frost have passed. This means that the frost tender plants can now be moved out into the garden. But if you plan on growing any heat loving plants you would be wise to grow them under a garden row cover. The easiest to use is the floating row cover made of Remay (spun polyester), which don’t require any types of supports. It is so light that the plants will grow right up into it. You can use it to give a speedy start to warm weather vegetable seedlings as well as direct sown seeds. Another good idea when starting seeds outdoors is to gauge the soil temperature. Many seeds will not germinate at low soil temperature and may rot before the temperatures are right for germination. A good soil thermometer is essential to guage when to plant seeds as well as transplant seedlings.
- Plant seeds or set out seedlings of frost sensitive annuals. Because color sells you will find many of these plants in bloom in very small cell packs. It is much more desirable to buy plants that are not yet flowering. Instead focus on good green foliage and sturdy stems. Some frost sensitive annuals to consider are Ageratums, Annual Asters, Caladiums, Calendula, Celosia, Cleome, Coleus, Cornflower, Cosmos, Dusty Miller, Gazania, Geranium, Globe Amaranth, Hollyhocks, Impatiens, Marigolds, Lavatera (Mallow), Annual Lobelia, Nasturtiums, Flowering Tobacco, Petunias, Pinks (Dianthus), Portulaca, Salvia, Snapdragons, Statice, Sweet alyssum, Wax Begonias and Zinnias.
- Make sure rose beds are clean of past years debris which can harbor diseases like Blackspot and Powdery Mildew. If they appear you can control them with fungicide like NEEM OIL 3-IN-1
- Allow spring flower bulbs leaves to ripen. Now is the time when next years flowers are forming. Camouflage yellowing foliage with quick growing annuals or perennials.
- Check your irrigation systems now before they are needed this summer. Don’t wait until natural rainfall requires supplemental irrigation.
- Monitor weekly rainfall using a coffee can and measuring stick or buy a rain gauge at your local garden center. When weekly rainfall is less than 1 inch supplemental irrigation may be necessary. When in doubt dig down 8-12 inches and see if the soil is uniformly moist.
- Weeds are becoming more active so this is a good time to use mulches to smother them.
- Visit local public gardens this month. Mother’s Day is a favorite day to visit a garden. Bring a notebook to jot down ideas and plant combinations for your garden.
- Deadhead Rhododendrons, Azaleas, Mountain Laurels and Lilacs as the blooms fade. This directs more of the plants energy to new growth and flower buds for next year.
- Prune early blooming woody plants that bloom on previous season’s growth if necessary. Prune these plants right after they finish flowering: Cherries, Magnolias, Lilacs, Rhododendrons, Azaleas, Dogwoods, Mountain Laurels, Forsythia, Flowering Quince , Flowering currants,Pieris.
- Prune late blooming woody plants that bloom on current season’s growth. Glossy Abelia, Butterflybush , Beautyberry , Shrub Althea, Oakleaf Hydrangea, Goldenraintree , Hybrid Tea Rose.
- Last call to transplant small trees and shrubs. Take advantage of the natural rainfall and cooler weather.
- Pinch back new soft growth of needled evergreens if you wish to control their growth and keep them compact and bushy.
- Last call for spring lawn feeding and pH correction. Test your soil for Nitrogen Phosphorus and Potash and pH with a soil test kit before fertilizing or liming for best results. Lawn mowing begins in earnest. Check length weekly and strive not to cut more than 1/3 of the existing growth at a time.
- Plant tender summer bulbs like Calla and Canna Lilies, Dahlias and Gladiolus.
- Bring plants overwintering indoors back outside slowly now that the last frost has passed.
- Many houseplants can be brought outside onto shady decks later in the month.
- Fuchsias can be brought outdoors in partial sun areas or on decks in containers or hanging baskets.
Continued vigilance is necessary on slugs and aphids, which appeared last month. Both can reproduce without having to find a mate so their populations can build quickly. Aphid females can lay fertile eggs without the benefit of male input (called oogenesis) and slugs, like snails are hermaphroditic enabling them to fertilize their own eggs. Use a natural slug bait to control slugs. To control peach tree aphids on roses and other plants use the aphid chaser. On other plants you can use yellow sticky traps or spray the aphids with a insecticidal soap.
Later in the month you may see Tent caterpillars. The population of this moth can fluctuate over a 3-10 year cycle. The tell tale sign is the large tent like silk web spun by the caterpillars as they feed on trees and shrubs. The caterpillars hide in the tent during the day and feed at night. The eggs started hatching out later in the month and so it is the best time to control them before they damage plants. Tent caterpillars will head down to the ground to pupate in July. The adult yellow-brown moths emerge next spring and lay eggs for next years generation. The first line of defense is physical removal of the nests. The best time to catch the caterpillars in the nest is when they are not feeding from dusk to a few hours past dawn. Soak the tent, caterpillars an all in a jar of rubbing alcohol. The second line of defense is to use a highly selective insecticide that won’t hurt potential predators. Spray trees and shrubs with Bt (Bacillus thuringiensis var. kurstaki). If you can reach put the spray nozzle inside the tent as well. The caterpillars must ingest the spray that coats the plants leaves. Another good organic control when the tree or shrub is not blooming is neem oil. In addition to spraying it is a good idea to apply sticky tree bands (on single trunk trees) that will catch any remaining caterpillars as they move down to the soil to pupate.
Vegetables, Herbs & Fruit
- Plant Asparagus roots and Potato and Sweet Potato Tubers, Strawberry plants.
- Plant seedlings of frost sensitive warm weather vegetables like: Cucumbers, Melons, Pumpkin, Squash & Zucchini, Tomatoes, Peppers, and Eggplants. Use a row cover or cloche to increase growth rate.
- Plant seedlings of frost sensitive warm weather herbs like Basil, Sweet Marjoram, Dill, Summer Savory, Perilla, and Cilantro. Use a row cover to improve germination and growth.
- Plant seeds or seedlings of perennial herbs like lemon balm, anise hyssop, chives and bee balm.
- In the middle of the month sow directly the garden cool weather crops from seed to extend harvests or plant overwintering types (like sprouting broccoli)of vegetables like Broccoli, Cabbage, Carrots & Parsnips, Cauliflower, Lettuce, Radishes, Leeks & Onions, Greens, Beets, Spinach & Swiss Chard.
- Sow directly to the garden warm weather crops like Beans (pole and bush), Corn, Cucumbers and Squash & Gourds when soil temps get above 60 degrees F. Check temperature with a soil thermometer.