It's May! It's Spring!
What to do in your garden ...
May is a frantic month in northern hemisphere gardens. Spring is winding down and summer's just around the corner. Warm weather changes rapidly to hot weather. The middle of April and the month of May is one of the best times of the year for our local gardens. Everything is bursting with bloom, color and health (including the blue cranesbills in the photo above).
At Deep Roots we are positively overflowing with spring and summer color, annuals, perennials and natives. In my garden just about everything is in bloom – roses, clematis, flowering vines, cranesbills, irises, geraniums, foxgloves, sweet peas, solanum, sisyrinchiums (both the blue-eyed plant and the creamy-yellow sisyrinchium striata below), viburnum, fuchsias, and my hydrangeas
are almost there… coming through blue as I have been assiduous in applying hydrangea blueing powder throughout the year. Also in bloom are my tomatoes and my pomegranate tree but they will not set fruit until the weather is consistently warmer. My potatoes are doing very well… I am just waiting for the flowers to appear and the plants to die back a little before I start searching in the soil for those warm and lovely little new spuds.
You may not need a list of what to do in the garden in May, because it is staring you in the face every time you walk through your garden, but here is the last burst of garden chores to get done before serious heat sets in:
WEED! WEED! WEED! It’s important to catch the weeds while they are still small because they will compete with your other plants for nutrients, water, and light. With the rain we’ve had recently, weeding is the biggest and most important job in the garden right now. It is essential to regularly pull up weeds and grass that grow in your flower beds, as once they set seed you will find it hard to ever get rid of them entirely. Pull them out!
If, like me you are invaded by the perennial morning glory, you must pull it up wherever you find it, as it grows 9” a day from every node at this time of year. Turn your back on it for one week and it will have grown over 6 feet in all directions!!! Originating in tropical America, morning glory – scientific name Ipomoea Indica pictured below) –forms a dense blanket of foliage over all vegetation. Its bright purple flowers look gorgeously pretty in this photo, but they are a sinister facade for a vicious strangling vine, known to put down strong roots wherever it touches the soil. It grows rapidly to the top of any tree canopy where it blocks light, reduces photosynthesis, encourages disease, prevents germination and breaks down trees. This vine will complete,y cover this garden room in one season if left to grow. I love its blue flowers but I hate the way it smothers everything else in the garden with its huge heart shaped leaves. Pull it out! Do not confuse this perennial vine with the annual morning glory vine. This pretty 15’ vine is easily grown from seed and dies back in the fall. We have Morning Glory seeds at Deep Roots.
PESTS. As the weather heats up, so do pest problems. To help identify what’s bugging your plants and find a solution, bring a sample of the affected plant into Deep Roots in a sealed plastic bag and ask one of our nursery associates to identify the problem and suggest a cure. Examine your tomato foliage regularly for tomato hornworm (photo left). Keep watch for aphids, cabbage caterpillars, cutworms, scale, slugs & snails and any signs of fungal diseases (leaf spot, mildew, rust etc.). Hand-pick or wash off any pests you can see. Spray with a suitable insecticide if the problem persists. We have several insecticides at Deep Roots, both organic (safe for use on vegetables and fruits) as well as non-organic.
SNAILS AND SLUGS are out in force and can do a lot of damage in a short period of time. Go hunting for them early in the morning before they have had a chance to get under cover. I throw them into the road and leave them there for the crows to feed on. If you do not have the time or the inclination for this, we have a selection of slug bait from the mildest to the most effective. On your roses, watch for saw flies. Pay attention to the undersides of the leaves, looking for pale-green, caterpillar-looking slugs. They will strip a plant bare if you don’t pay attention. Spray your plants to wash these pest off, but if it begins to get out of hand, thoroughly spray with spinosad, including the undersides of the plants. Watch for caterpillars and stay ahead of an infestation. Some caterpillars will turn into beautiful butterflies, so don’t over react when you see your first one or two. Just pay attention to those of your plants that tend to get the most infested. The first line of defense is a birdfeeder. The theory is that it attract birds to the garden and they will look for other food, i.e. caterpillars and aphids, on the plants nearby. If all else fails spray with BT – Bacillus thuringensis or Spinosad. These will kill caterpillars only, leaving beneficial bugs alone.
LADYBUGS: Talking of beneficial bugs…who doesn’t need more ladybugs in their garden?! Buy a little bucket of these beauties and invite your neighborhood kids over one evening for a release party. Priceless…..
MULCH: a two-inch layer of organic matter such as LGM Planting Mix and Mulch around your annuals, perennials, trees and shrubs (taking care not to cover any stems or tree trunks) to suppress weeds, and hold in moisture while giving the garden a finished appearance. When the weather warms up it will also keep the roots cool. Mulching around roses is a great way to keep them evenly moist and help prevent fungus growth by reducing water splashing and spreading spores. NOTE: Don’t mulch around warm season vegetables now because they really need the heat around their roots.
LANDSCAPE: Start digging that pond you’ve been talking about. Clean bird feeders. Turn the compost pile. Rip out invasive plants before they spread even further. Clean up any drooping or ragged fronds on palm trees. Treat yourself to a water feature or garden fountain. It will attract birds and other wildlife to your garden.
POTS. Before planting in new clay pots, pre-soak them in a bucket of water for 5 or 10 minutes. If you plant in terra-cotta when it is dry, it wicks moisture from the soil. Wash old, used clay pots in a weak 10% bleach solution before re-using them.
LAWNS. Keep mowing the lawn regularly. It's the best thing you can do to control weeds and keep grass thick and healthy. Fertilize your warm season lawn grass in May. If using a granular fertilizer, add flour to the spreader. This will help you see where you’ve been so that you won’t over fertilize.
PRUNING: Prune winter and spring flowering shrubs such as azaleas and camellias when they finish blooming because they bloom on year-old growth. This will stimulate new growth that will bear flowers next year. If hibiscus, lantana, princess flower, and other sub-tropicals have become leggy and awkward, cut back by as much as half to reshape. Pinch back your fuchsias and salvias to prevent legginess and promote fuller plant growth.
DEADHEAD. Remove fading flower blossoms before the plant goes to seed. Once a flower has set seed its botanical work is done and it will not bloom again, putting all its energy into the seeds.Deadheading will keep your garden neater and prolong flowering. Begin replacing cool season annuals as the blossoms fade.
THIN OUT the new fruit on your deciduous fruit trees to about one fruit about every six inches.
PLANTING: Plant or transplant trees and shrubs before the heat of summer. Plant vines such as jasmine, mandevilla and clematis for spectacular colorful flowers. Continue to plant warm-season flowers such as sunflower, verbena, zinnias and petunias, ageratum, amaranthus, aster, bedding begonia, bedding dahlia, candytuft, celosia, coleus, coreopsis, cosmos, gloriosa daisy, impatiens, lisianthus, lobelia, phlox, marigolds, nicotiana, portulaca, sunflowers, sweet alyssum, verbena, vinca and zinnias.
PERENNIALS. Shop for late summer and fall bloomers like asters, coreopsis, daylilies, gaillardia, gaura, gloriosa daisy, heliotrope, penstemon, pentas, purple coneflower and salvias. Make sure tall perennials are staked. Sow seeds or plant seedlings for tomatoes, beets, cantaloupes, cucumbers, kohlrabi, okra, pumpkins, corn, green beans, melons, peppers, squash, eggplant, lima beans, and summer and winter squash.
WATERING: Keep up with watering. We will probably not see any more significant amounts of rainfall this spring. Even highly drought-tolerant plants can need irrigation in hot weather. Water large cacti, for example, once a month and agave and yuccas every three weeks. Make sure your irrigation is turned on, and make any repairs if you haven’t already.
STOP WATERING. When foliage on garlic, bulb onions, and shallots begins to dry out on its own, that’s your cue to stop watering. The lack of water prompts bulbs to form the dry outer layers that allow them to be stored.
FERTILIZER: This is the growing season so continue fertilizing your lawn, roses, citrus trees, fuchsias, avocado trees, vegetables, and flowers. Fertilize and deadhead your repeat blooming roses after the flowers fade to encourage a second round in early summer. When applying granular fertilizer, avoid getting it on the foliage to prevent fertilizer burn. For quick greening of your lawn choose Marathon All Season Lawn Fertilizer.
IRON DEFICIENCY. A sign of iron deficiency or "chlorosis" is yellow or pale leaves with green ribs. Chlorosis is a symptom of the plant being nutrient deficient, and therefore unable to produce adequate amounts of chlorophyll. The photo on the left shows a plant which has chlorosis caused by iron deficiency. The plant's newest leaves become more yellow than normal, with the veins on the leaves being the last part to turn yellow. A plant's inability to take up iron is usually the result of one of two causes. 1) the soil is deficient in iron, or 2) the chemistry of the soil prohibits the uptake of iron. Many plants cannot properly absorb iron from the soil if it is too alkaline. Severe chlorosis can kill a plant and must be addressed. The soil and city water in our region are both highly alkaline therefore chlorosis in our plants is more than likely the result of alkalinity in the soil. Apply a fast acting soil acidifier such as Hydrangea Blueing Formula. If you do not see results in a few days then the soil may be iron deficient, in which case apply chelated minerals such as Grow More EDDHA iron chelate which is formulated to work in alkaline soils. Citrus trees are very prone to suffering from chlorosis and benefit from regular soil acidification. We recommend Grow More Citrus Growers Mix.
NOTE: Yellowing leaves can also be a sign of over-watering as in this plant on the left. Usually however, the whole leaf is yellow, including the ribs. To avoid over watering get a water meter here at Deep Roots and test the moisture in the soil before watering.
HOUSEPLANTS. Re-pot houseplants in new soil (we recommend cactus mix for faster draining) and move into a slightly bigger pot if they are root bound. Move them outdoors for their summer vacation when/if nighttime temperatures stay consistently above 60 F.
BULBS. Don’t cut off the still-green foliage on spring blooming bulbs that have finished blooming. Leave the tops on to help provide sustenance for the bulbs for next year. Don't remove them until they have finished their job and turned brown. If your bulbs have multiplied substantially, they may profit from digging, separating, and being held over in a cool, dry place to be replanted next fall.
CAMELLIAS, AZALEAS and RHODODENDRONS: Start feeding these acid loving shrubs with an acid fertilizer such as "Dr. Earth Azalea, Camelia and Rhododendron Fertilizer"when they stop blooming. Use at half-strength so you can feed again two or three more times. Fertilize at 6-8 week intervals, finishing up at the end of September.
CYMBIDIUMS: May begins the main growing season. Good summer care is important Keep the plants in semi-shade. Cut off bloom spikes and fertilize with Grow More Growth Formula. If your plants have outgrown their containers transplant them no later than the end of June. If you wait, you may not get blooms next year.
EPIPHYLLUMS are still blooming so continue to cut off faded blossoms and mist frequently in hot weather but don’t over water. A good rule of thumb is to water when the soil is dry down to 1-1/2 inches.
DAHLIAS: Give your dahlias a low nitrogen fertilizer. The goal is not such vigorous green growth, but those beautiful flowers. Thin out the number of buds to increase flower size.