Q & A with Master Gardener Peter Coppola

Questions and Answers with Master Gardener Peter Coppola

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Dear Master Gardener,
I have an existing lawn that sustained some significant damage. I could repair the damaged area or I can replace the entire lawn. I am considering replanting the entire lawn with environmentally friendly Pearl's Premium grass seed? It is expensive but is it worth it? Any advice or tips? Thank you.

The Master Gardener’s Answer
You did not identify the source of the damage; I am guessing it was a onetime incident related to something like construction equipment. The decision to repair the damaged areas or replace the entire lawn is one of scale; how much of the lawn is damaged (more or less than half,) how big is the lawn, how healthy is the lawn (are there other bare spots beyond the damaged areas,) when was the last time you thatched or aerated, and are there a lot of weeds growing in among the grasses? If the damage is to more than half the lawn it might, MIGHT, be worth doing the whole lawn. If less than half the lawn is damaged; raking out the damaged spots, topdressing with compost, and over-seeding may be all you need to do.

Regarding the choice of seed; we live in a climate where cool season grasses grow best. They are the fescues, ryes, and blue grasses; and there are dozens of each variety. A healthy lawn contains a mix of all three varieties. The reason is that they green out at different times in the spring and go dormant at different times in the summer; that ensures a green lawn over a longer period of time. Also, if a disease or insects kills one variety the other two will still keep growing.

The variety and quantity is listed on the back of every bag of lawn seed, and they vary according to the site; sunny, shady, play area. Everyone who packages lawn seed have their own mixes. I do not know if any one mix is better than another, I do know that the condition of the soil is more important than the mix of seed and I would put more effort, and money, into augmenting the soil with organic matter rather than selecting seed mix.

Regardless of your choice; take the time to consider reducing the amount of lawn and replacing it with planting beds. Less mowing, less watering, less fertilizer and pesticides = more family time!
Dear Master Gardener,
Thanks so much for offering your insight. I am new to gardening. I built 2 small (24”x48”) raised vegetable beds, and also have several 12-14”d deck pots (which I have previously used for flowers and herbs). Since this is clearly not the time to seek in-depth advice at a garden center, any tips for getting started that you can offer would be greatly appreciated!

I’d love to plant some combination of tomato and pepper plants, as well as maybe lettuce, cucumber and/or broccoli; but I’m not sure what’s realistic in my limited space. Are the large pots a possible option for any of these?

The Master Gardener’s Answer
Bless you for thinking about vegetables! Our first garden, way back in the last century, was 4 by 8-feet and our harvest was one softball sized winter squash. We have expanded our garden over the years and that includes container plants on the back porch. Container plants are higher maintenance, but you can grow any vegetable in a container.

Peppers, tomatoes and cucumbers are warm season plants, meaning they grow well during the hot summer months. If you have pepper and tomato seeds, start them indoors now; if not purchase seedlings towards the end of May. You can start the cucumber from seed in a couple of weeks when average outdoor daily temperature is above 70 degrees. Consider growing a bush variety.

Lettuce and broccoli are cool season plants and need to reach maturity before late June when it gets too hot and the plants begin the end of their life cycle by bolting. You can start cool season plants from seed outdoors now.

I am all about production. You can grow several lettuce plants in one container, but only one broccoli plant, producing one head, per container. It is all about the math. The recommended spacing for broccoli is 2 feet apart. That means every broccoli plant gets 4 square feet of growing space. That is the equivalent of 28 gallons of micro rich soil versus a 5 gallon container. I would lean towards herbs and bush beans for your containers.

Dear Master Gardener,
I have a non-invasive Miss Molly Butterfly bush. I thought I had more time to prune it but it is just starting to leaf in spots. Usually it’s later in the season. Is it too late to cut back?
The Master Gardener’s Answer
The butterfly bush does not set its flower buds in the fall; it blooms in the summer on new season stem growth. Even though it is just beginning to leaf out there are no flower buds; so it is not too late to prune it now.

Dear Master Gardener,
I have a question about a beautiful tricolor Chinese willow (Salix integra 'Hukuro-nishiki). I bought it about 4 years ago as a shrub and over the years it has grown into more of a tree. I have several questions about it. With more regular/aggressive pruning, can I maintain this gorgeous planting as a shrub?

The Master Gardener’s Answer
The variegated dappled willow is a beautiful specimen plant that can grow as high as 10 feet with a diameter of 7 feet. It is a shrub from the willow family grafted to the top of a willow tree trunk. You should be able to see this by following the branches back to the trunk where they converge at the same spot. That may be the reason it is now more tree-like than shrub-like.

Bear in mind that you only prune for the health of the plant. On the priority list, appearance is last. That said, if it is not a grafted plant then yes, you can be aggressive and prune it back to a manageable size. It can be pruned back aggressively in late winter and it will be more of a ball shape, or you can prune back a third of the growth on a 3 year cycle and it will retain a more natural appearance. If you find that the any of the growth is different from the variegated pink, whites, and greens, that is a sign that the tree is growing through the shrub and those branches need to be removed completely. Never prune back to the graft, as you encourage the tree to send out branches.

Dear Master Gardener,
I have a question about a beautiful tricolor Chinese willow (Salix integra 'Hukuro-nishiki). I bought it about 4 years ago as a shrub and over the years it has grown into more of a tree. Is its root system invasive?

The Master Gardener’s Answer
It is a willow and the roots will take off well beyond the diameter of the plant -- in your case about 15 feet. If it is near a septic system or sewage line, then you may have cause for concern.

Dear Master Gardener,
I have a question about a beautiful tricolor Chinese willow (Salix integra 'Hukuro-nishiki). I bought it about 4 years ago as a shrub and over the years it has grown into more of a tree. Is there a slower growing, dwarf version of this shrub? If so, please provide specifics.

The Master Gardener’s Answer
I am not aware of a slower growing, smaller version of the shrub. The place to check is at a garden center, they in turn, can check with their suppliers.

Dear Master Gardener,
Could you please recommend a variety of low maintenance, dwarf shrubs/evergreens for foundation plantings in Zone 6?

The Master Gardener’s Answer
The question that has vexed landscapers for 80 years; “How do I hide that ugly foundation?” The number of dwarf plants are too numerous to mention, just about every plant today has a baby sibling. The place to locate them is at a garden center -- they will carry more varieties than the box retailers and their staff can help you with special orders.  

But before you motor over, you need to do some homework. To properly landscape your foundation you need to take some images of the planting area, take measurements and make a scale drawing, and include notes like exposure, the compass direction the foundation is facing, and large trees or hardscapes that impact the area. Identify underground utilities like electric/water/irrigation system, and sewage pipes that are in the planting bed. Sketch the size and shape of the plants at maturity and develop a list of foliage and flower colors that complement the house color. Armed with your sketch, the nursery will be able to point you to plants that will most satisfy your plan.

If you want to minimize maintenance, you have to ignore the size of the shrub in the pot, and stay true to your sketch. The biggest mistake homeowners make is planting too close together because they look so lonely by themselves. Focus on the planting label, it will provide information like the spread of the plant at maturity. If you want the shrubs to show their true shape, or be able to walk behind the plants to perform maintenance on your house you need to plant accordingly! During those first few years, the space between the shrubs can be filled with annuals or herbaceous perennials that can easily be relocated as the shrubs reach maturity.

Dear Master Gardener,
I put lime on my lawn 3 weeks ago. (powder type, not pelletized). When can/should I lime again? My yard is part shade (sun in early morning and late afternoon because neighbor’s trees shade our yard). My “lawn” is a mixture of grass, violets (not blooming yet), very healthy moss, and weeds. I’m fine with the mix including the moss. Thank you.
The Master Gardener's Answer
I am happy that you are enjoying your lawn just the way it is. I, too, am fine with my untreated lawn except I pull the violets and dandelions.
Back in the day, and by that I mean before my time, old timers talked about applying lime to sweeten the soil. That was a time when the pH test was performed by taking a handful of moist soil and touching it to the tongue. If it tasted sour the pH was low (below 6.0), if bitter the pH was high (above 8.0); midrange (7.0) was the sweet spot.
Lawn grasses prefer a pH of 6.5-7.0 and that is your target when spreading lime. The question is not how often you should apply lime, but how much lime should be applied; and I can tell you that you are not applying enough.
The area where the very healthy moss is growing with the grass has a pH somewhere below 6.0, where there are violets with the moss it is around 6.0. That is because moss prefers a medium acidic soil pH. If the soil pH were in the sweet spot there would be no moss.
Send a sample of soil out for test, or invest in a pH meter; and then based on the readings follow the directions on the lime package to determine the amount to apply.

Dear Master Gardener,
Two years in a row, I've lost all squash to the vine borer. Last year, I used special pheromone traps that did capture some of the borers but I still lost all plants. Is there a way to beat this pest?
What vegetable plants are worth planting for a good yield and high pest resistance? My best luck was with pots on the porch with cherry tomatoes, cukes, romaine and some herbs, while the ground garden did poorly, even string beans, which were good in years past.

The Master Gardener's Answer
Trying pheromone traps tells me you would like to avoid chemical solutions, and I applaud you for that. So let’s look at the actions you can take to control the pest through its life cycle which begins with:
The clear winged adult moth emerge in late June early July about the time the squash plants begin to bloom. This is when the pheromone traps help, but you can also check inside the blooms and physically relocate the moths to a can of water with a pair of tweezers. If you are going to use a pesticide, this is the time to use one.
The next stage is the eggs, tiny brown ovals scattered on the ground near the base of the plant. Scrap them up with a trowel and crush, bury deeply, or put them in the compost bin there will be no food for them when they hatch.
Since the eggs are next to the squash plant, the larvae do not have to go far to begin boring into the vines. All you can do here is look for something like wet sawdust under a vine, cut a lengthwise slit in the vine to expose the borer, squash it, and cover the vine with soil. Back in the day when Burlington farmers were growing Hubbard squash for market high school students were hired to do this work.
When the larvae finish gorging on your plant it borrows into the ground and transitions to the pupae stage. Right now the cocoon is one to two inches underground where the squash grew last season. Turning the soil every season will destroy a lot of them.
To keep the borer in check you need to clean to clean the garden of debris yearlong, rotate the plants to make the larvae work for their food, and build up the soil with organic matter.
Healthy plants are capable of taking care of themselves with physical and chemical defenses. There is a reason for those thorns on the squash stems, they keep pests from climbing and emit a poison; we get itchy arms the pests go legs up. As you continue to improve your soil with organic matter, rotate drops (maybe add peas and dry beans to the rotation), and maintain cleanup, plant performance and yield will improve.

Dear Master Gardener,
My tomatoes are in large pots. I am using Promix (peat-moss based medium, the most generic one).  Do you have any suggestions for how to deal with the blossom end rot that plagues my tomatoes? Thank you for your help!

The Master Gardener's Answer
Blossom end rot is a watery blister at the bottom of many vegetables; tomatoes, peppers, eggplant, and squash. It is caused by a calcium deficiency in the fruit. The root cause (no pun intended) can be; inconsistent watering, when the soil is dry plant growth slows and when wet it grows quickly and the demand for nutrients like calcium exceeds the supply; too much fertilizer, increases the amount of salts in the soil reducing nutrient intake; low pH, tomatoes prefer a slightly acidic soil pH range of 6.0-6.8  When the soil moves through medium acidic to strongly acidic at a pH of 5.5, the ability to acquire calcium from the soil is cut in half.

Sphagnum peat moss, the primary ingredient in Promix, has a pH below 4.0 but lime is added to the mix to bring it up to above 6.5. Promix also contains a timed released fertilizer to minimize burning the plant. So I suspect the culprit is inconsistent watering, and that is a big problem with container grown plants. If you feel you need to try other solutions, you can check the soil pH before you plant and you can add some compost to the mix prior to planting. Here's a pH chart.

pH chart

Dear Master Gardener,
I hear a lot about pesticides being bad for bees. How do I maintain my lawn without pesticides?

The Master Gardener's Answer
Pesticide is an all encompassing term for products that kill; bugs (insecticide), diseases (fungicide) and plants (herbicide.) The operative word here is kill; and pesticides are bad for everyone.

Pesticide manufacturers provide all that safety information on their packaging for a reason. The recommendation to wear a respirator and personal protection equipment, and to spray when there is no wind is to protect you and passersby. The instructions caution that toddlers and small pets should not play on the lawn for several days because they might become sick.

Smaller wildlife - birds, toads, garter snakes, assassin bugs, lady bugs, dragon flies. These are the good guys and represent more than half of the population. Then there are the microbes, where good guys outnumber the bad 30,000:1. Pesticides kill all of them.

The solution to maintaining your lawn without pesticides is to quit cold turkey and undo the damage chemicals have caused. Use an organic fertilizer, top dress and thinly spread compost or cow manure, use a mulching mower. Try corn gluten meal to inhibit weed seed germination, and milky spore bacterium to control grubs. All of that will feed the microbe and insect population, bringing the soil back to life. You will still see pests but they will become fewer and fewer as the good guys take back the lawn.

That will take several years and you will have to do some things like pull a few weeds by hand, but it will all be worth it when you see worms aerating the soil, dragonflies patrolling the yard, and all those bees pollinating your flowers and vegetables.

Dear Master Gardener,
Do I put some fertilizer in my garden before I put the mulch down?

The Master Gardener's Answer
As a general rule you should always lightly till the soil to work granular fertilizer in after spreading it around your plants. This helps for several reasons; the fertilizer break down more quickly; the fertilizer stays where you put it and this minimizes runoff, and it reduces the chance that birds will confuse it as grit and eat it. Birds eat tiny pebbles (grit) to help them digest their food. Granular fertilizer is just the right size. If you already have the fertilizer, spread it around the planting beds before you mulch.

Dear Master Gardener,
At the beginning of April I planted peas. Nothing sprouted. Is it too late to plant again? Something ate all the peas and broccoli last year before anything was ready to harvest.
The Master Gardener's Answer
Peas are usually one of the easiest seed to germinate. As a cool season plant, it will germinate at a minimum soil temperature of 40 degrees. Even though daily air temperatures this year were below average, the soil temperature was over 40 degrees, although not by much. Another culprit could be that the above average amount of rainfall this year kept the soil so wet that the seeds rotted before they could germinate. I suspect that both in combination might have been responsible for your pea problem.
So, is it too late to re-sow? Peas are ready for harvest 60 to 70 days from germination; if you sow now you will be harvesting in July when the cool season plants have finished their life cycle or have gone dormant. You can give it a try and you will have a harvest, but not as plentiful as usual. You might want to consider waiting until August and sow a fall harvest.
Did something eat the pea and broccoli plants? If so, probably rabbits and/or woodchucks. You may need a better fence. Did they eat the pods and florets? Add chipmunks and squirrels to the list of varmints; if you have a large population in your neighborhood you may want to invest in netting.  

Dear Master Gardener
How on earth do I get my grass as green as everyone else’s in the neighborhood?
The Master Gardener's Answer
How green is green? At this time of season, the grass on a typical non-fertilized lawn should be light (Kelly) green in color. Environmental conditions like soil health, rainfall, and sunlight have an impact on sugar production (photosynthesis). The higher the availability of sunlight and water, the more chlorophyll cells are produced and a darker green. Houses, garages, fencing shade the lawn, and large trees compete for both sunlight and water; all of that leads to lighter shades of green.
If you bag your grass and have not fed the soil microbes any organic matter the grass will be lighter. If you use a mulching mower and have a lot of organic matter incorporated into the soil the grass will be a little darker. But I do not believe that is the green you are asking about.
In order to get that deep (Emerald) green color like everyone else in the neighborhood you need to add fertilizer; and if you apply fertilizer you need to water the lawn to dissolve the fertilizer. But here is the rub; you will enter a minefield.
Before you apply fertilizer to your lawn you need to have the soil analyzed and maintain a record of all fertilizer applications. All of the requirements and penalties for non-compliance are incorporated under state law: 330 CMR 31.00: PLANT NUTRIENT APPLICATION REQUIREMENTS FOR AGRICULTURAL LAND AND NON-AGRICULTURAL TURF AND LAWNS.
Also, the town is currently under a full outdoor watering ban:  “Anticipating reductions in staffing levels Board of Selectmen approves Full Outdoor Watering Ban effective as of April 1, 2020 until October 31, 2020; No irrigation of lawns via sprinklers or automatic irrigation systems, No irrigation (by hand-held hose or otherwise) to establish a new lawn and new plantings….”
You are at the lawn care crossroad; which of the paths will you chose?

Dear Master Gardener,
Bleeding hearts are so beautiful when in bloom, but when they’re done, they are done. How can I keep this plant looking healthy all summer long?
The Master Gardener's Answer
We love bleeding hearts! I have two large clumps in the backyard that are shaded by shrubs and a maple tree. This is important because they are cool season plants. Their optimum temperature range is 55-75 degrees and they die back when it gets too hot. You can extend their appearance by keeping the soil moist, but you cannot keep them healthy and growing all summer long.

Dear Master Gardener,
My Bleeding heart plant has grown bigger than most of my shrubs!  It is huge! Do I need to split this every year and if so, what time is best?
The Master Gardener's Answer
The plant does get big, and you can keep it in check by pruning after it blooms; but it will die back in summer. Propagation by division can be done in early spring or fall using a spading fork or shovel. That will reduce the amount of plants, but they will still command the space when they grow. If/when the plant dies back and the gap in the landscape is too large, then go ahead and divide it. An alternative solution is to interplant a warm season plant with similar sunlight requirements, like Astilbe, to grow and fill the space left when the bleeding heart dies back.

Dear Master Gardener,
The lawn where I live was lush in May. Organic fertilizer is used and no grub control. Fertilizer was applied and in a week the lawn was brown. They don't water it either, but in the past this hasn't been a problem. The lawn is in full sun. What happened?
The Master Gardener's Answer
Let’s take it from the top. Grass is a cool season plant. When the air temperature approaches 80 degrees it begins to go dormant, growth slows to a stop, and without water the plant will brown out. This May was the hottest month on record, and rainfall this year is running 4-inches below average. As you walk around town you will see that lawns that are not artificially irrigated have browned out. Fertilizer, organic or not, compounds the problem. Nutrients in the fertilizer are in the form of salt and need to be diluted in order to become available to the grass plants. That requires watering. The reason you did not see this problem the last four years is because rainfall totals were above average throughout the growing season. The grass went dormant but we received enough rainfall to keep it green.

Dear Master Gardener,
My irises don't bloom. Any suggestions?
The Master Gardener's Answer
Irises do not compete well with each other. At a minimum they need to be dug up and divided every five years. The obvious sign that it is time to divide is the reduction in blooms. The image is of one five year old plant, you can see that there are no blooms on it.

The cycle is:  year one - plant in organic rich prepare soil; year two - more new plants and some blooms; year three - lots of blooms; year four - diminished blooms; year five -  time to divide.

Dear Master Gardener,
I have peonies that do not bloom. I have had them for years and they look healthy. Should I replant elsewhere? Any suggestions?

The Master Gardener's Answer
Peonies are a great anchor perennial for the flower bed; properly planted they can go for decades with minimum maintenance. You said the plants are healthy - that eliminates insects and diseases as possible problems. There are just a few more reasons they do not bloom.
peonies part 1
Location – Peonies do not do well in shade. Plant them in an area where they receive a lot of sunlight
Soil Preparation – Incorporate as much organic matter as possible into the soil before you plant. Skipping this step leads to applications of fertilizer, and too much fertilizer leads to beautiful foliage with few blooms.
Over Fertilization – Too much fertilizer results in beautiful foliage with few blooms.
Planting Depth – The eyes on the plant roots should not be more than 2-inches below the soil level. I have seen established plants where the eyes were above ground and the plant still bloomed beautifully, but the less than 2-inch depth is a must.

I suspect you maintain your beds by keeping them weed free and mulching. I further suspect that over the years the mulch has built up to where the eyes are more than 2-inches deep. Wait until early October when the 2021 eyes are clearly established on the roots. Dig up the plants, prepare the soil, and replant. You should have beautiful displays next year.

Dear Master Gardener,
My butterfly bush has bloomed but only the tips are flowering. The rest of the bloom is brown. Some of the blooms never flowered. The rest of the plant is healthy. I had the same problem last year. It gets full sun. No pesticides or fertilizer was applied. I water by hand infrequently. Does it need fertilizer?

The Master Gardener's Answer
The Butterfly Bush, or Buddleia, is very easy to grow. So easy that in some states, it is considered a weed. That does not mean that it is free of problems. Set it in a sunny location with limited competition from other plants and leave it alone. It does not need to be fertilized, and too much water will drown the roots and kill it.
Butterfly bush
I can see from the image that along with dead flowers, you have some chewing insect damage, but the plant itself looks healthy. My first thought was that the chewing insect transmitted a disease into the plant, but I think that would have resulted in more severe damage.

I have never seen bloom damage like this and thought I would take a walkabout in search of similar flower damage on other plants and I did not have to walk far. Right outside my door were hydrangeas with the same sad blooms and that led me to the following conclusion.

Ninety degrees is pretty much the upper limit for Buddleia and I suspect high air temperature was the culprit. The flowers are actually an inflorescence, a bunch of flowers on one stem, the lower flower buds did not survive the high temperatures and the buds that developed after the heat wave are now opening.

We are in the midst of a heat wave and we had a similar heat wave about the same time last year. I think this is one of those problems that you have to accept as outside of your control to solve.

Dear Master Gardener,
Could you please share the recipe for "Feel Good Spray," and advise on which plants to use and how often?

The Master Gardener's Answer
Gladly, and thank you for requesting the recipe and providing me an opportunity to talk about it. The “home brew” fungicide has been around in print for as long as I can remember, and floated online since the birth of the Internet. It is about as non-chemical as you can get while indirectly improving the chances of your plants staying healthy.

The primary ingredients are liquid dish detergent and ammonia mixed in water. The dish detergent is a wetting agent that breaks the magnetic bond between water molecules, reducing runoff and increasing percolation; meaning the water stays around the plant roots where you want it.

Ammonia is a cleaning agent that when mixed with the dish detergent, acts as a disinfectant. It exists naturally in humans and the environment, as anyone who has kicked a pile of decomposing grass clippings can attest to. The ammonia that we purchase is about 5 percent the strength of that produced naturally.

Feel Good Formula
For a quart sized spray bottle
1 tablespoon dish detergent
1 tablespoon ammonia f
Fill bottle with water

For a gallon jug
¼ cup dish detergent
1/4 cup ammonia
Fill jug with water

For a hose end sprayerhose end sprayer
A hose end sprayer is used on large areas.
Place equal amounts of dish detergent and ammonia in the cup and it self mixes as the water passes through the hose nozzle.

Collectively; water (H2O), dish detergent (Na,H,C,O,N) and ammonia (NH3) are a combination of hydrogen, oxygen, carbon, nitrogen and sodium. They represent 97 percent of a plant’s chemical composition.

I mostly use the spray every two weeks on my vegetables. About mid-August when powdery mildew appears I spray my herbaceous perennials.

Arguably this spray has a negligible positive impact in the garden but it makes me feel good using it and that is what gardening is all about.