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Articles by Dr. Francis Gouin

Add soil-testing to your spring chores

High winds have cluttered lawns and gardens with branches and debris. Rake thoroughly to remove anything that might be propelled into the air by a fast-spinning lawnmower blade. Don’t add yourself, your pets or your windows to the statistics of lawnmower injuries.
    While you have the lawnmower in operation, raise its deck to four inches and push it through the flower garden. This is a great way of pruning the top of the perennials and annuals and pulverizing them into mulch. This natural mulch will not suffocate the roots. Leave the stems of annuals in place to help maintain the mulch. Both stems and roots of annuals will contribute organic matter to the soil.
    This is a great time of year to prune the buddleia to the ground. Don’t be afraid. Butterfly bush is nearly impossible to kill. I have seen it grow in thatch roof on houses in England.
    Spring is also time to divide perennials that are becoming crowded. I like using a Japanese gardeners’ knife or a hatchet with a hammer to divide perennials with crowns that are difficult to pull apart by hand. Use the knife or hatchet to divide the top of the crowns down to the roots, then pull the roots apart. This method helps you recover a greater portion of the roots. If you are dividing a large clump, discard the center portion, which is generally the oldest and the most susceptible to rot.
    Clumps of ornamental grasses also need dividing. The center of large ornamental grasses tends to die out, resulting in a donut appearance. Before digging the clump, use your power hedge clipper to prune back the top. You can make the top into mulch by cutting the stems into four- to six-inch lengths and letting them lie. Cut the stems as close to the ground as possible, and don’t worry about cutting a few new green shoots.
    Root-prune the clump close to the outer edge by sticking the blade of a sharp shovel perpendicular to the ground and pushing until its top is flush with the ground. Repeat this step around the entire clump. Dig a ditch around one-half the circumference of the clump before trying to wedge the root ball from the opposite side of the ditch. With the root-ball above ground, use an ax and a sledgehammer to divide the clump into smaller clumps four to six inches in diameter, saving only those divisions along the outer edge. Discard all crowns close to the center of the clump. These are the oldest crowns and prone to rot.
    If you are a friend of the Bay, want to save money and desire the best lawn and garden ever, have your soil tested. If you have been fertilizing your lawn and garden year after year and/or have not applied lime, there is a good possibility that you could have problems. Excess levels of phosphorus in the soil cause nutritional problems. Your soil may be too acid to grow plants efficiently. Or the organic matter in your garden soil could be too low.
    Only a soil test will give you the information to correct the problem and help you become a better gardener. Go to www.al-labs-eastern.com and follow the instructions. If you would like the Bay Gardener to review the test results, include my name and email, dr.frgouin@gmail.com, and they will send me your results.
    Do not include a crop on your form, which will save you a few dollars. But I will need to know what you are growing to make the proper recommendations, so e-mail me crop information separately. I do not charge Bay Weekly readers for my recommendations.

To recover from cold weather and salt, your landscape needs TLC

It’s been a hard winter for plants as well as for us. Damage to landscapes reminds me of the winter of 1976-’77, when the Bay froze as far south as Norfolk. Compounding problems are the tons of salt and chemicals used on roads, sidewalks and driveways. On state highways alone, 480,000 tons of salt were spread this winter, more than double average usage over the past four years.
    Everywhere you look, you’ll see symptoms of winter injury to plants. The foliage of many ground cover plants such as liriope, pachysandra, St. John’s wort and creeping junipers is brown and brittle.  Many azaleas, Japanese hollies and camellias have dead branches, and many small flowering trees have broken branches from the weight of the snow and ice.
    Most of the ornamental plants used in landscaping are survivors. With patience and time, they will recover and resume growth come spring — providing their roots were not killed by low temperatures.
    Roots are not as cold-hardy as the aboveground stems and leaves. If the majority of the roots are growing in mulch as a result of over-mulching, it is highly possible that the roots died in killing temperatures of –4 degrees. If the majority of the roots were killed, the entire foliage of the affected plants will gradually turn brown as daily temperatures rise. The only solution is to wait and see. If half or more of the plant dies, it means replacing and avoiding future over-mulching.
    For injured ground cover, the best solution is to adjust the cutting height of your lawn mower to about three inches and mow the tops down so they won’t look so conspicuous. Most likely the roots of these ground covers have survived and the new growth will emerge form the crowns or rhizomes. Dead branches in juniper ground cover will have to be pruned away one dead branch at a time. Junipers are conifers and cannot rejuvenate unless there are live green or gray-green needles firmly attached to the stems.  If the entire plant appears dead, then the only choice is to replace it.
    Dead branches on azaleas, rhododendrons and Japanese hollies need to be pruned back to a main stem or branch that is alive. If the entire stem is dead, cut it within a few inches of the ground. If the root system is alive, these plants can regenerate from the stumps on stems smaller than one inch in diameter.  Recovery will be slow, however, and it may be best to replace the plant.
    Do not try to bolt together broken branches on trees and large shrubs. This will only result in rot problems in the future because the sapwood has already been exposed to rot-causing organisms. Bolted together, they will rot from the inside out. Broken branches should be pruned to a healthy stem with the cut made perpendicular to the broken branch. Never make a flush cut with the stem. If the bark on the stem has been damaged, use a sharp knife or chisel to smooth the bark and exposed sapwood so as to promote the growth of callus tissue. Do not paint with tree-wound dressing.
    Damaged grass and plants along sidewalks or driveways may be dead. Do not fertilize as this will only contribute to the salt problem. The best solution is dilution. Spade a one-inch layer of peat moss with a dusting of limestone into the affected layer to dilute the salt concentration to a tolerable level. During the growing season, the sodium concentration will be further reduced by leaching.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. Please include your name and address.

On lawn and garden; never in the compost pile

If you’re burning wood, you get ashes. A reader asked if he could dump his ashes in the compost pile. My answer was a resounding no.
    Wood ashes are basic in nature and contain high levels of oxides, making them very reactive in raising the pH. Composting systems perform at their best when the feedstocks — those materials that are undergoing decomposition — are slightly acid. So adding wood ashes to an active composting pile will delay and/or stop the composting process.
    Store wood ashes in covered metal containers and keep them dry. They should never be stored in an open container where they can absorb water. I can remember watching my grandmother pour dishwater over a bed of wood ashes to extract a lye solution she used to make lye-soap. (Remember the song “Grandma’s Lye Soap”?) I can also remember the strainer she used becoming very hot after the lye water had drained away.
    Wood ashes are best applied directly on the garden or on the lawn. Ashes must be cool and dry when they are applied. Ashes spread in a garden and covered with dry leaves can start fires. I know because I’ve seen it happen.
    When applying ashes on lawns with a fertilizer spreader, first screen them through a half-inch screen to remove pieces of charred or raw wood. Directly from the container, they should be spread as uniformly as possible; use a lawn rake to spread them around to avoid creating hot spots that can kill the roots of the grass. Spread the ashes on a calm day, avoid inhaling the dust and wear safety goggles to avoid eye contact.
    In general, I recommend spreading a five-gallon pail of wood ashes over 100 to 200 square feet, especially on lawns. Higher levels can be applied on garden soils that are to be rototilled.
    Wood ashes are a tremendous source of calcium, potassium and some phosphorus as well as essential trace elements. If you are using wood ashes to maintain the pH of your lawn or garden, have your soil tested to avoid excessive high soil pHs and to assure that your soils contain adequate amounts of magnesium (Mg). Wood ashes tend to be almost free of magnesium, which is essential for the manufacturing of chlorophyll in plants.
    Save some of your wood ashes to spread around the zucchini plants this summer to help in controlling the stem borer. Before the zucchini plant starts spreading, apply a thin layer about two-feet wide around each plant. It will not provide 100 percent protection, but it does reduce infections.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. Please include your name and address.

One-step potting

Larger seeds — such as those of broccoli, cabbage, cauliflower, eggplants, marigolds, peppers, tomatoes and zinnias — can be direct seeded into the containers in which they will grow until they are ready to be transplanted into the garden. This eliminates the shock associated with transplanting. Direct seeding requires more space initially, but these large seeds do not require the tender care essential in germinating small seeds.
    They will germinate easily providing you keep the rooting medium moist but not wet.
    The container size you select for direct seeding will depend on the rate of growth of the species and the size you want the plant at transplant time. For most vegetable transplants and most flowering plants, three- to four-inch pots will be adequate.
    However, to produce tomato plants or pepper plants with fruit already well formed by the time you transplant them in the garden, you need two stages. To produce such plants, direct seed into three-inch pots. When the plants are eight to 10 inches tall, transplant them into six- to 10-inch pots. Transplant them before the roots circle the inside walls of the three-inch pots.
    To start all these larger seeds, fill the three-inch pots with commercial potting medium such as Pro-Mix, Sunshine Mix, Metro Mix or Farfard Mix to the top edge of each pot. Unless the seed packet indicates that seed germination is 100 percent, which is highly unlikely, place at least two seeds in the middle of each pot and press them in the soil lightly with your fingers. If you are using seeds that you stored from previous years, sow at least three seeds in each pot. As seeds age, germination is reduced.
    Irrigate each pot thoroughly until excess water drains from the bottom.
    Seeds of broccoli, cabbage, cauliflower, celery, Chinese cabbage, kohlrabi, pak choi and lettuce germinate best at temperatures of 65 to 70 degrees. Sow them in March to be tall enough to transplant into the garden in early to mid-April while temperatures are cool. To prevent sunscald, acclimate the plants by placing them in trays outdoors under light shade for at least a week before transplanting them to the garden.
    Seeds of tomatoes and peppers germinate best at temperatures near 80 degrees. Soon after the seeds have geminated, place them in full sun. Never allow them to dry out.
    Because seeds of peppers, both hot and sweet, are slow to germinate, they should be sown in March
    Like tomatoes, seeds of calendula, gazania, gaillardia, marigold, sunflowers and zinnia germinate rapidly and their seedlings develop rapidly. Delay starting these seeds until five or six weeks before you plan to transplant them into the garden.
    If you wish to grow your plants organically, blend any of the potting mixes with one-third by volume compost such as crab or lobster waste compost, which will provide all the nutrients the plants need until they are ready to be transplanted into the garden. Otherwise, within six weeks of germination, you will need to initiate a liquid fertilizer program.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. Please include your name and address.

Transplanting seedlings

The sooner you can transplant seedlings after they germinate, the better they can survive and continue growing. Delay transplanting your seedlings after they have become crowded and have true leaves, and you’ll get stunting, resulting in slower growth.
    The first green leaf-like structures you see on seedlings are called cotyledons. The cotyledons contain all the energy necessary for germination and the development of the first true leaves. To minimize transplant shock, transplant seedlings soon after the first true leaves appear.
    Small plants grow rapidly, and the sooner you transplant them the faster they grow. Transplant bedding plant seedlings into individual three- or four-inch pots in cell packs such as 804. Metro-Mix, Sunshine Mix, Farfard Mix or Pro-Mix can be used as a transplant medium. These commercial blends have sufficient fertilizer to supply the needs of the transplants for six weeks. Eliminate the need for later fertilizer by blending one-third by volume compost made from lobster or crab waste with the commercial mix.
    Your growing medium must be moist, neither wet nor dry. Using the point of a plant label or the point of a knife, lift each seedling or clump of seedlings from their growing medium. With the same instrument, separate the clump of seedlings into individual plants. Using your fingers, lift each seedling by gently grasping the cotyledon. Never lift young seedlings by grasping the stem. The stem is the permanent part of the plant while the cotyledons are only temporary structures engineered to drop from the stem as soon as the plant becomes well established. If you accidently squeeze the stem, you can permanently stunt the plant’s growth.
    At this point of development, the seedling will require full sun. Minimum temperatures should not drop below 65 degrees. The containers should be irrigated only when warm and dry to a fingertip pressed lightly on the surface of several containers.
    Consider conditioning the plants by placing them outdoors in partial shade for at least a week before transplanting them into the garden.  
    Seeds of cabbage, broccoli, cauliflower, peppers and lettuce should be sown now, from late February through early March. Seeds of tomatoes should be sown approximately five weeks before they are to be transplanted into the garden — unless you desire to transplant tomato plants with tomatoes already attached to the stem.
    A certain amount of pride comes with growing your own bedding plants from seeds.

Coming next week: One-step potting.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. Please include your name and address.

Sow slow-germinating seeds now

As you know from last week’s calendar of when to sow what, now into early March is the time to sow seeds of onions and shallots, begonias and coleus, petunias and impatients. These very fine-seeded species require special treatment. Here’s what to do.
    Buy a commercial seed starter that’s a sterile fine mixture of peat moss, pine bark and fine vermiculite amended with limestone to adjust the pH to near 6.5.
    Sow onions and shallots in four-inch pots with drainage holes. The seedlings will grow in these containers until you transplant them to the garden. Fill the pot to the top with seed starter; scrape away the excess. Bounce the bottom of the pot several times on your work surface to eliminate air pockets. Smooth the surface of the growing medium. Now uniformly spread 30 to 40 seeds over the surface. Watering the seeds will cover them with medium as it causes additional settling.
    The seeds will germinate best at temperatures between 75 to 80 degrees. The top of the refrigerator supplies the heat to make an ideal germinating table. As soon as seedlings appear, move the pots to a window facing south for maximum sunlight — or into a greenhouse. Irrigate as needed. Fertilize after seedlings have grown two to three inches tall. Use either fish emulsion or a diluted commercial water-soluble fertilizer.
    For starting seeds of begonia, coleus, impatients, petunia and so on, salad trays — the plastic kind you fill at salad bars — are ideal. Using an ice pick or a pointed knife, punch holes uniformly across the bottom, spacing the holes one inch apart. Punch from the inside out. Next add at least one to two inches of seed-starting mix. Using plant labels, divide the surface area of the starter mix so that each species gets approximately two by two inches. Scatter the seeds uniformly over their area, label each species and sprinkle with water until the excess drips out the container’s bottom. Snap the clear cover closed and place the container on top of the refrigerator.
    As soon as the seeds start to germinate, move the container to a window facing south or to a greenhouse. To prevent the build-up of heat within the salad bar container, lay a pencil or wooden dowel half-way between the hinge and the front edge of the container, across the length of the container and wrap with a rubber band to keep the cover partially closed. The seedlings will be ready to transplant into larger pots as soon as they can be lifted.

Next week: Transplanting seedlings.

Here’s what to sow when

It’s time to start on your garden.    
    Sow slow-germinating small seeds inside in late February through March. These include begonia, celery, impatient, petunia, snapdragon, etc. These small seed plants are not only slow to germinate but slow to grow.
    Wait until March to sow larger seeded plants. Broccoli, cabbage, Chinese cabbage, cauliflower, kohlrabi and pac choi should be sown so that the plants will be tall enough to transplant into the garden in early to mid-April while temperatures are cool. The seeds of these plants also germinate and grow best in cooler temperatures. To prevent sunscald, acclimate the plants by placing them in trays outdoors under light shade for at least a week before transplanting them into the garden.

What’s Next for Forced Bulbs?

Q  My forced bulbs, amaryllis and paperwhites, have finished flowering. What can I do to bring them back next year?
    –Sandra Olivetti Martin

A  Are the bulbs in gravel or in soil in pots? If they are in gravel, plant them in a mix of half potting soil-half compost, put them near a window facing south and keep them growing until you can plant them outdoors in full sun come spring. In soil, give them some liquid fertilizer. Next fall after the leaves have died back, dig up the bulbs, plant them in pots, place them near the foundation of the house on the north side and mulch heavily with leaves held in place with chicken wire. Near early December, bring in a few pots of potted bulbs and start forcing them. Do not fertilize them again until they have flowered.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. Please include your name and address.

    Because seeds of peppers, both hot and sweet, are slow to germinate, they should be sown in March, under 80-degree temperatures. Pepper seeds require two to three weeks to germinate and seedlings are slow to grow initially.
    Seeds of tomatoes, calendula, gazania, gaillardia, marigold, sunflower and zinnia germinate rapidly, and the seedlings also develop rapidly. Seeds of these species can be delayed five or six weeks before they are transplanted into the garden. This prevents the seedlings from becoming root bound, which will permanently stunt their growth. If you want to grow extra large plants, start them in five- and six-inch containers.
    Many seed catalogs publish seeding schedules, but you must know your climate zone and growing conditions, such as growing in a cool or heated greenhouse or on the window sill. The heated greenhouse in full sun provides the ideal growing condition, while the window sill is the least desirable situation for growing plants, especially those that require full sun.
    If you are growing plants on a window sill, rotate them daily (weekly if that’s the best you can do) to prevent them from leaning toward the light. Follow the same rule if you have a lean-to greenhouse that faces south.
 

That means you forgot to feed them

Are your azalea leaves yellowing and dropping? The loss is more than winter’s toll. You could have prevented it if you had mulched your azaleas with one or two inches of compost in early to mid-September or applied one-quarter cup of an ammonium-based fertilizer soon after the first frost.
    Lacking that help, nitrogen is now translocating from the older leaves to the flower and vegetative buds at the ends of the branches. During late fall and winter, buds are enlarging in preparation for spring when the flower buds open and vegetative buds produce new stems. If the roots of plants cannot provide sufficient nitrogen to the ends of the branches after the plants have stopped growing in the fall, nitrogen from the older leaves will migrate out of these leaves and move up the stem to where terminal flower and vegetative buds develop. Nitrogen is the only plant nutrient that can move about after its initial distribution when plants were in active growth. The translocation of nitrogen is most active in the fall when temperatures are above freezing.
    The leaves of white-flowered azaleas yellow before falling. The leaves of red- and pink-flowered azaleas generally turn red to purple-red just prior to leaf drop.
    This same problem occurs with American holly, especially female hollies that produce an abundance of berries. The production of holly berries requires an abundance of nitrogen. If the roots cannot supply the nitrogen needed, buds will rob the nutrient from the leaves. However, with hollies, the nitrogen is translocated rather uniformly from all of the existing leaves, which causes the uniform yellowing of the foliage. Under severe nitrogen-stress, hollies will drop leaves extensively.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. All questions will appear in Bay Weekly. Please include your name and address.

Give plants the right lights, and they’ll grow in any season

Plants don’t like freezing temperatures any more than we do. But many will be perfectly happy to grow indoors, encouraged by fluorescent lights.
    Under lights, you can grow plants, including vegetables, up to 10 inches tall.
    Success depends on choosing the right setup. Many systems are on the market, but not all are of equal quality. Beware of those made entirely of chrome-plated steel. They are susceptible to rusting from the fertilizers used for growing. Chrome-plated shelves and trays are especially vulnerable. Stainless steel or plastic-coated shelves and trays will outlast all others.
    Nearly all the lighting fixtures are designed to hold Grow-lux fluorescent bulbs. Grow-lux lights emit both the blue and red rays of light, and both are necessary for photosynthesis and flower production. For maximum effectiveness, the uppermost foliage of the plants must be placed within inches of the light source. Grow-lux lights are recognized for their light quality and not for their light intensity.
    To improve the light intensity of your growing chamber, consider including a warm white fluorescent bulb for every two Grow-Lux lights in the light bank. Adding warm white bulbs is especially important when growing tall plants or plants with varying heights. Only warm white fluorescent bulbs emit the red light essential for photosynthesis with sufficient intensity to penetrate the foliage to a depth of eight to 10 inches. Cool white fluorescent bulbs emit only low levels of blue light, which is not as essential for photosynthesis as red light.
    High intensity lighting fixtures can be built using a combination of power-groove fluorescent tubes and 60-watt incandescent bulbs. This sort of setup is used to supply lighting in commercial growth chambers. However, these power-groove fluorescent tubes generate so much heat that fans must be used to circulate the air.
    Meeting the irrigation needs of plants growing under artificial lights can be challenging. Plants growing under Glor-lux lights require less water than plants growing under warm white fluorescent lights due to cooler rooting media temperatures. Because the red waves from warm white fluorescent bulbs penetrate deeper, rooting media are warmer and dry out faster.
    Avoid overcrowding plants under artificial lights. As the plants increase in size, provide additional space for them. A good rule of thumb is to never allow the foliage of one plant to touch that of an adjoining plant. Allowing the plants to grow under crowded conditions will give you tall spindly plants with weak stems and yellowing leaves at the bottom.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. Please include your name and address.

But learn their tastes, and they’ll give you flowers

Are your African violets blooming?    
    If not, read on to learn why and what you can do to bring out the flowers.
    African violets’ long-standing popularity grows from lush foliage and their habit of winter flowering. The plants are challenging, but not more than many in-home gardeners can manage. Even propagation is possible with a little knowledge on your part.
    African violets are shade-loving plants whose leaves scorch under the direct rays of the sun. Grow yours in places where they receive only diffused light. Or try growing lights.
    When you re-pot, use only a rich organic rooting medium that has been sterilized. You’ll find the right mix at garden supply stores, or you can sterilize your own in the microwave. Heat a gallon of moist rooting medium for 10 to 12 minutes on high.
    African violet varieties are vast because these popular plants have been hybridized extensively. Cultivars range from miniatures to larger than normal, with varying types of petals, flower colors and velvety foliage.
    Not all the hybridizing has produced good qualities. In breeding, some desirable characteristics such as disease resistance, wet-soil tolerance and plant vigor have been compromised. Many of the new cultivars require special care. Some want to be grown in sterile rooting media. Others demand extreme care in watering, refusing to tolerate over-watering or wet foliage. Still others can’t abide fertilizer accumulation along the edges of their pot. Even winter flowering has been lost in some cultivars.
    African violets are picky about temperature. If they don’t like the temperature where they live, they won’t flower.
    Many of the new cultivars will flower consistently only when temperatures remain constant. Older cultivars flowered best where temperatures were warm during the day and cool at night. The windowsill was often the best place for growing African violets. Today’s African violets are best grown in the middle of the room where temperatures remain more constant.
    It’s still true that you should avoid wetting the foliage when watering the pots. If you typically water from the bottom up, change over once a month and water from the top down to prevent fertilizer salts from accumulating along the top edge of the pots. Accumulated fertilizer salts will burn the petiols, or stalks, of the lower leaves in contact with the edge of the pot. Fertilizer salts appear as tiny gray-green granules clinging to the inside edge of the pot starting from the surface of the rooting medium. If you’ve got them, scrape them off.
    Have I answered all your questions about raising African violets? If not, write and ask and I’ll reply.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. All questions will appear in Bay Weekly. Please include your name and address.