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Articles by Dr. Francis Gouin

Hardy ornamental plants will survive, so shape them as you want them

Be ruthless. It’s time to chop ornamental grasses and butterfly bushes. Cut them down to the ground.
    Also remove the old flower stems and old foliage of sedum to make room for new growth.
    In addition, it’s time for serious pruning of lilacs that are over-grown or infested with stems borers. Trim azaleas, rhododendrons, cherry laurels and hollies that make it impossible to look out of the bedroom or living room windows. Some of the branches that you cut can be brought in and forced to flower.
    Late winter and early spring are the best times for hard pruning. The roots of all ornamentals growing in your landscape are packed with sugars, carbohydrates and nutrients just waiting to move upward into the stems to produce new branches and leaves. Hardy ornamental plants survive and flourish no matter how drastically you prune them. So you don’t need to fear killing the plant if you remove too much.
    Cut those clumps of ornamental grasses as close to the ground as possible. To eliminate the need to carry away the old dry stems, cut them into pieces six inches or smaller and allow them to become mulch. While you are at it, cut those stems of butterfly bushes as close to the ground as possible. I use a chainsaw to prune my butterfly close to the ground, forcing new branches to emerge from the roots. If the forsythia and weigela shrubs are over-grown or not flowering well, cut those branches close to the ground as well. This is how you force the new branches to originate from the roots and not from branch stubs.
    Overgrown azaleas, rhododendrons, hollies, yews and cherry laurels should have their branches pruned to 12 to 18 inches lower than the desired height. You will avoid having to prune them again in a few years, and regrowth will have a more desirable appearance.
    You don’t have to be a certified professional horticulturist to know how to prune hardy ornamental plants. These plants are survivors and dormant vegetative buds up and down the branches are waiting to burst into active growth. That plant will recover and appear normal in a relatively short time. Trust me.


Plow Pan Is Your Problem

Q    We have been growing perennials, a few annuals and various vegetables and herbs on the same large garden plot for about 13 years. I’ve noticed that the plants aren’t as healthy as they once were, despite the fact that we’ve added soil and fertilizer over the years. What do you recommend to improve the soil for the garden overall and in particular where the perennials are located?
      –Amanda Gibson, Lothian

A    If you have been gardening in the same area for 13 years, and have been tilling or plowing each year, most likely you have developed a plow pan about six inches below the surface of the soil, and it is now affecting drainage and root penetration. The only solution is double digging or sub-soiling. To test my theory, sharpen a broom handle (or use a piece of half-inch pipe) and see how deep you can push it into the ground. Test several areas in your garden. If you can’t penetrate deeper than six inches you have plow pan and need to dig below. If you have a tractor, I have a sub-soiler you can borrow.

Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Asparagus is coming; winter weeds should be going

If you planted a cover crop of winter rye or wheat last fall, most likely the grass is six to 12 inches tall by now. Use your lawnmower to mow the grass as close to the ground as possible. Mowing saves you time in tilling the soil and helps to dry it, making it easier for the tiller.
    Ground left bare will by now be covered with a carpet of chickweed and henbit. Use horticultural vinegar to kill these winter weeds now before they drop their seeds. For maximum control, spray the vinegar on the foliage during a bright sunny day. Within 24 hours, you will see the weeds turn yellow-white with the leaf margins going brown. Friends report good results with a mixture of one gallon of distilled white vinegar with one-quarter cup of Palmolive dish detergent.
    If that bare ground is your asparagus bed, once the weeds have died down, rototill lightly, delaying if the soil is very wet. Before tilling, you can easily remove old stems because most have rotted at the base. Allow the tines of the tiller to penetrate the soil no more than three or four inches so as to not disturb the roots of the asparagus plants, which will soon be sending up shoots
    Readers have asked how to grow white asparagus, which are tenderer than green asparagus and have a milder flavor. White asparagus are grown in the dark. The old method was to hill the beds with soil or sawdust as the spears appeared above ground. The modern method is to build a lightweight frame of wood and cover it with black plastic or roofing paper. As soon as the spears appear, place the covered frames over the beds, lifting every two or three days for harvesting.
    If you have not had your soil tested in the past four years, now is the perfect time to submit a good representative soil sample for testing.
    I recommend sending the soil samples to A&L — now Waypoint Analytical — in Richmond (www.soilandplantlaboratory.com/services/soilsampling.aspx).
    If your soil is a sandy loam or loamy sand, have it tested for all trace elements especially for boron (B). However, if your soil is a loam, silt or clay loam, the general soil test will suffice.
    If you have been growing multiple crops each year, you most likely will need to apply limestone. If you want me to make the recommendations, don’t specify a crop (a savings of $3-$5) and include my email so I’ll get your results: dr.frgouin@gmail.com. Once I have them I’m happy to consult you.


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It’s not such prickly work after all

A Bay Weekly reader who has tried and failed many times asks how to grow cactus plants from seeds.
    It’s possible. Here’s how.
    For growth, cactus plants need full sun, dry conditions except for a few days of rain in the spring, sandy rather poor alkaline soil that’s hot in the day and cool at night. These are exactly the same conditions you must satisfy to be successful in germinating seeds. 
    To prepare a seed germinating mix, blend one-fourth cup of garden soil with two cups of play sand and one rounded teaspoon of agricultural grade dolomite limestone. Moisten with water and mix thoroughly. Place the mix in a metal or Pyrex pan and bake at 200 degrees for one hour, cooling in the oven. By doing this, you are pasteurizing the soil to kill all weed seeds and living organisms that are not common under desert conditions. Put two tablespoons of the sterilized soil in a clean, sterile container or plastic bag. Place the rest of the sterilized soil in a clean, shallow four- or five-inch pan with drainage holes in the bottom.
    Uniformly scatter cactus seeds over the surface of the mix, allowing one-eighth to one-fourth inch between them. Cover the seeds with the saved pasteurized soil using a tea strainer. Water the seeds carefully with a rose bulb or fine sprinkler until water drips from the bottom of the container. Place the pot near a window facing south where it will obtain full sun all day and cool temperatures at night.
    Commercially, cactus seeds are germinated in lighted cycling chambers with 80 degrees of bottom heat for 12 to 15 hours under grow lights and nine to 12 hours of darkness at temperatures 60 to 65 degrees. You can best achieve the commercial germination chamber with a gooseneck lamp with a 40-watt incandescent light bulb. Adjust the light to 10 to 12 inches above the pot and place both in the middle of a room. Turn the light on soon after you rise in the morning and turn it off before going to bed at night. The heat and infrared rays of the incandescent light bulb will not only provide light but also warm the soil during the day. When the light is off, the soil will cool.
    Most packets of cactus seed contain several species, so germination is very erratic, anywhere from a few weeks to a month or more. Check for soil moisture daily. If the soil feels warm, irrigate lightly. If the soil feels cool, withhold irrigation.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Put yourself in its place

Oh, the stories I’ve heard of abuse to cactus. I’ve spent many afternoons and evenings in plant clinics where people wheel in large barrel or drum cacti with decaying centers. Often water was oozing from the bottom where it had begun to rot. One elderly lady arrived in a chauffeured limousine. She sent the chauffeur inside to bring me out to examine her plant, a three-foot-tall Saguaro cactus. Before she would allow me to examine her cactus, she requested my credentials.
    My first question to her, and to the other cacti owners I advised, was where the plant was kept at home. Most often, I was told, in the middle of the living room.
    Where do cacti grow? The desert.
    Cacti growing as houseplants need to reside in an area with full sun.
    Cacti are succulents and store large amounts of water in their cells. Because the epidermal layer is thick between the spikes and covered with a chitin like material, they lose little water by evaporation. In the home, most cacti should not be watered more than once a month and should only be fed with a liquid fertilizer once a year.
    They’ll need repotting every four to five years. The soil can be made by blending 10 percent garden soil with 90 percent sandbox or builders sand. To each cubic foot of cacti soil, add one-half cup of agricultural limestone and blend thoroughly. Heat garden soil at 200 degrees for one hour to kill weeds, insects and worms or grubs.
    Because most cacti have sharp spines, they are dangerous. To handle them, crumble many sheets of newspaper into large, tight balls. Put the paper balls over the spines, pressing firmly into place until you can no longer feel the sharp ends.
    To remove a cactus from its pot, slide a long sharp knife along the inner side the container and the root ball. Tip the container on its side and slide out the root ball. If the root ball does not slide easily, strike the bottom of the container with a rubber hammer or with a two-inch-thick board cushioning a carpentry hammer to prevent breakage.
    The new container should be at least three inches larger in diameter than the old and one to two inches deeper. Measure the depth of the original root ball and add soil to raise the top of the root ball to within one inch from the top of the pot. Stand the plant upright and lift into the middle of the new container. Wear thick gloves and get your hold on paper, not spikes. Use your repotting mix to partially fill the space between the root ball and the wall of the new container. Then wash the new soil into place with a steady stream of water. Add more prepared soil and water until the new soil is level with the top of the root ball.
    For large cacti, repotting will require several hours of intensive labor.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

It’s time to start onions and peppers

Onion and pepper seeds are slow to germinate and slow in their early stage of seedling growth. So if you’re growing them from seed, you want an early start. Now’s the time.
    Sow the seeds in a sterile potting mix rather than garden soil to avoid sprouting weeds and contaminating your seedlings with soil-borne diseases. Fill the pots a half-inch from the top. Tap the pot on a bench several times to eliminate air pockets. Firm the potting mix by pressing three or four fingers across the top of the mix. Sprinkle the seeds across the smooth surface, and lightly cover with fresh potting mix. Use a rose bulb or a fine sprinkler to lightly moisten the potting mix until you see water dripping from the bottom of the pot.
    Germinate these seeds in total darkness at constant temperatures of 75 to 80 degrees. How to get those conditions?
    Once excess water has drained from the bottom of the pot, cover the top with plastic and put it on top of the fridge or near the furnace where temperatures are relatively constant. Check the pots daily to make certain that the potting mix does not dry. Moisten accordingly.
    Onion plants grow in their original pots until it’s time to move them into the garden. Sow their seeds a quarter- to a half-inch apart to give them room to produce thick stems and larger root systems to better survive transplant. Sown closer than one-quarter inch apart, onion seeds will grow thin and spindly seedlings too weak to survive transplant in the garden. To accommodate a good population of seeds, use a six- to eight-inch diameter pot three to four inches deep.
    Pepper seeds can be sown closer together because you’ll transplant the individual seedlings into separate pots as soon as their true leaves appear. The first leaf-like growths are not leaves but cotyledons that provide energy for germination and early growth. Do not transplant the seedlings until you see true leaves.  
    Using a pencil or other object, lift each seedling from the potting mix. Grasp the seedling only by the cotyledon. Grabbing the stem or leaves may harm the plant, but the cotyledons are temporary and will separate from the plant under the shade of the leaves.
    To produce strong, healthy plants for your garden, transplant into four-inch pots in the same potting mix the seeds were sown in.
    Check the potting mix bag to see if it contains added nutrients. If nutrients have been added and if compost is part of the blend, water the pepper seedlings until the excess drips from the bottom of the pots.
    If the mix is free of nutrients or compost, add half the amount of water-soluble fertilizer recommended by the manufacturer. Fertilize at the full rate as soon as active growth begins.
    The amount of nutrients generally added to potting mixes is adequate for approximately one month. After that, use a liquid fertilizer as recommended by the manufacturer.
    Give the young the plants full sun. Check daily to maintain proper moisture.


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Small gardens can yield big rewards

Short on space or sun but longing for your own fresh vegetables? You can garden with as little as a square foot of space. Dwarf varieties of vegetables grow successfully in limited space, including planter boxes. You can find them in the seed catalogs arriving by mail this time of year.
    Small or not, all vegetables need full sun. For that, no amount of fertilizer can substitute. So watch where the sun falls now, remembering that in full summer it will take a more northerly path. When you find your sweet spot, let its space dictate your garden size.
    When planning, double-cropping will maximize your growing space. For instance, Bibb lettuce and green onions can grow together. In one square foot of space, you can grow four Bibb lettuce plants and eight green onions planted between the lettuces. As soon as you harvest the lettuce, be ready to plant more. As the season will have advanced, this time choose Summer Time lettuce. This variety is heat tolerant, but because it grows larger than Bibb lettuce, only two plants can be grown in one square foot of space.
    You can grow one miniature cabbage plant and eight radishes in a single square foot. The radishes will be ready for harvest in 24 to 30 days, leaving plenty of room for the cabbage to grow.
    Also available in miniature form are bush-type cucumbers and summer squashes. Hot pepper plants by nature tend to be small and highly productive.
    A small-space garden can also have tomatoes. Cluster varieties produce an abundance of fruit in a limited amount of space. The Tiny Tim variety takes up little room in a garden and produces excellent fruit.
    If you yearn for snap beans, consider growing pole beans. Grow them on a trellis, but make sure bean leaves don’t shade the rest of your vegetables. To ensure they don’t block sunlight to other foliage, plant beans on the north side of your garden or make use of a nearby wall using coarse string for them to climb.
    Little Marvel is a delicious shelling pea that grows only 18 inches tall and produces well. I have even seen it grown in flower boxes with the vines hanging down, loaded with pods.
    Whatever you choose to grow, gardens in a limited space need well-prepared soil. A blend of equal parts compost and gardening soil will provide approximately 50 percent of the nutrient requirements. To maintain the soil, supplement with fertilizers at two- to three-week intervals. For container gardens, add about 25 percent sand by volume to the soil mixture for proper drainage.
    Keep your small garden properly irrigated. Water well and deep, avoiding daily watering except in wilting sun.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Here’s how I know which to trust

In winter’s grip, there is nothing like a good nursery and seed catalog, full of colorful pictures of thriving plants, to put you in the mood for digging in the soil. These books may even encourage you to build a small greenhouse or hot bed to get started early.
    Which is why mailboxes fill up with seed and nursery catalogs this time of year.
    I receive many more catalogs than I keep because I discard those with altered images or illustrations to describe what they have to offer.
    There’s a difference between an honest-to-goodness nursery or seed producer and the books sent by wholesale distributors. Most wholesale distributors publish thin-paper catalogs full of pictures that have been enhanced using intensive colored ink or have colorful illustrations of plants and fruit. They also tend to run specials such as two to three plants for the price of one or two to three packets of seeds for the price of one.
    On the other hand, a quality nursery or seed catalog business will most often provide a business history, including location and the number of family generations involved. They will also include information on breeding and propagating practices and photographs of their fields and staff. Most of this type of information is missing in catalogs of wholesale distributors.
    Did you know that by law, catalogs that advertise plants must include in the ad the scientific Latin name of the plant, including genus and species. This is because the English name of plants can change from one part of the country to another, while the Latin name never changes.
    I save good seed and nursery catalogs for at least three years, using older ones as references. All nursery and seed catalogs have sensational new introductions every year, most often posted on the first few pages. To learn if the variety has survived the test of time, I locate the new and improved variety that appeared three years earlier and see if it appears in the 2016 catalog. If I find that variety in the 2016 catalog with even more glorious description, I know that it has gained good reviews and they are bragging. If the description has not changed, it means that the variety is still under study.
    Seed and nursery companies are in business for making money. Their intent is to offer only what sells. Since thousands of dollars are spent in developing new varieties, they cannot afford to carry varieties that do not sell.


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Give them light, but go easy on water and fertilizer

In winter’s short daylight hours and cooler temperatures, houseplants require less watering and fertilizing. But they don’t want to be neglected. In winter and early spring, give plants as much light as possible. Even placing them near a lit lamp during evening hours will help considerably in keeping good health. Incandescent bulbs consume more energy, but because they emit red light waves that can be absorbed by the chlorophyll in the leaves, they are better for plants than LED or florescent bulbs.
    Fertilize at least monthly at half concentration. Follow the watering rule when you apply liquid fertilizer, adding enough water so that some drains from the bottom of the container.
    Poor watering is a problem I see often in troubled houseplants. Frequently, only the upper half of the root ball appears to have been watered. The lower half is as dry as the Sahara Desert.  Often, there is a visible line of fertilizer salts accumulating between the wet and dry regions with concentrations sufficient to burn roots in the fertilizer zone.
    Never apply slow-release fertilizers in fall or winter, as they are engineered to release their nutrients during active growth. Adding slow-release fertilizers now will likely cause fertilizer burn as they release nutrients faster because the soil is constantly at room temperature during this period of low light intensity and poor growing conditions.
    Don’t put African violets near a window. African violets perform best in diffused light and near-constant temperatures. In windows, the plants are exposed to cooler temperatures in the evening and warmer temperatures during daylight hours. Unlike many plants that would benefit from such a temperature change, African violets will cease to flower and may even exhibit cold damage on the foliage. Place them in the middle of a well-lighted room for more constant temperatures.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

What will happen come May?

Cherry trees starting to bloom, tulip and narcissus bulbs sprouting foliage and forsythia starting to show yellow. The record-high December temperatures are raising questions about many plants. Hardly a week passes without concerned neighbors or Bay Weekly readers questioning me. My answer thus far has been to leave things alone and wait to see what happens in the spring.
    Some things are certain. Flowering cherry trees and forsythia will have fewer flowers come spring. Tulip and narcissus foliage will most likely grow very tall, if the winter low temperatures are not severe. If they are, it will be killed to the ground, and new foliage will replace it.   
    Unless normal winter temperatures come soon, apple, plum, peach, pear and cherry trees may not produce a normal crop. Such species must be exposed to temperatures between 40 and 32 degrees for 100-plus hours for their flowers to open and be pollinated in spring. These low-temperature requirements are called stratification; unless they are achieved, neither flower nor vegetative buds will develop normally.
    Plant growth this spring will be erratic. There will be more lateral than terminal growth. Narrow-leaf evergreen plants such as pine, spruce and fir trees will appear fatter and not grow as tall. Deciduous trees such as maple, oak and birch will often have long terminal stems and few side shoots.
    However, there have been many benefits to this warmer-than-normal December. We’ve all had lower heating cost. Gardeners who planted fall crops such as kale, broccoli, cauliflower, collards, turnips, Brussels sprouts, rutabaga and spinach have harvested bumper harvests. The broccoli has been extremely tender and has produced an abundance of large side shoots. Cauliflower heads have been eight to 10 inches in diameter and extremely tender. Kale and collard have not stopped growing tender, new, young leaves, and some of the rutabaga has produced bulbous roots four to six inches in diameter.
    If you planted garlic in the fall, you should have leaves 10 to 12 inches tall. If you mulched them well with compost, you will be harvesting nice big bulbs come June. From the looks of my elephant garlic plants, I anticipate one heck of a harvest come July.
    It will be an interesting spring to observe some of the effects of climate change on our native and introduced plants.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

A healthy garden for a healthy life

Gardening is the most popular of all hobbies, and for good reason. Gardening gives you hours of relaxation and great satisfaction. It is good exercise. It forces you to go outside, bringing you closer to nature. It can be enjoyed by all ages. Getting children interested in gardening can have life-long consequences. On the other hand, you are never too old to start.
    Dorothy Frances Gurney, a poet of the late 19th and early 20th centuries, says it all in God’s Garden:
    The kiss of the sun for pardon;
    The song of the birds for mirth;
    One is nearer God’s heart in the garden;
    Than anywhere else on earth.
     In Maryland, ornamental horticulture is the second largest agriculture income-producing industry. In the U.S., it ranks third. Its popularity increases as we learn more about horticultural therapy and the benefits gained from eating fresh fruits and vegetables, especially growing your own. Organic gardening has also attracted many into the field.
    Gardens can range in scope from a few potted plants to flowers and herbs to vegetable gardens to an entire landscape. Whatever it’s size, your garden — and satisfaction — will thrive if you recognize that gardening is a science. Many problems can be avoided by following proven practices and by applying the knowledge gained by controlled scientific studies.
    As you imagine your garden over winter, keep a few of those proven practices in mind. Vegetables, fruits, many annual flowers and ornamentals want sun, so locate your garden where it will receive full sun. Nothing — not fertilizers, compost nor pruning practices — can substitute for full rays from the sun.
    Consider your soil, as well. Very few horticultural plants can grow in poorly drained soils. Acid or very alkaline soils are also factors, as many species have very particular preferences.
    Nutrition is as important to the success of growing plants as a proper diet is for our wellbeing. The benefits of organic matter not only include nutrients but also improved soil potential. Chemical fertilizers cannot always substitute equal benefits.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.