Wednesday, July 5, 2023

Pinch that sucker -- or not

They say there’s a sucker born every minute and it sure seems that way on tomato plants, except they’re branches. They're the new growth that sprouts at the intersection of a branch and the main stem of a tomato plant, and the long-standing advice has been to remove them by pruning or pinching them out.

To not do so is at your peril because it’s believed suckers steal energy from the plant. At least that’s the belief, except it’s not so. It’s one of those things that’s been done by gardeners forever because someone, somewhere, thought it was a good idea and no one thought to question it.

What is a sucker? On a tree, it refers to those fresh shoots that appear at the base of a tree. On a tomato plant, there are none. What are referred to as suckers are simply secondary branches, and with their leaves they contribute energy to the plant rather than steal it. These secondary branches will also develop flowers and fruit

So why have gardeners been removing them? First, we have to understand the two main types of tomato plants, determinates and indeterminates. Determinates were initially bred for commercial growers. This type grows only to a limited size and the fruit ripens more or less at the same time, making it much easier for mechanical harvesting. When grown as a large-scale commercial crop, determinate plants are not staked or supported, and you can be sure no one roams thousands of acres of fields, pinching off anything in sight that looks like a so-called sucker.

These smaller, bushier plants are suitable for the home gardener with limited space as they can be easily supported if need be with tomato cages, in ground or in a planter, so why bother with pinching off suckers if the commercial growers don’t bother — I’m getting to it . . .

Prior to the development of determinate varieties, most of the plants gardeners were growing in backyards in the old days were indeterminate plants. We still grow them, and many are heirloom varieties. They’re called indeterminates because they don’t stop growing. Tomato plants are vines and will grow that way when allowed, and for as long as conditions are suitable.

Indeterminates are also the type most often grown as hot house tomatoes in commercial greenhouses. There, they are allowed to grow and produce fruit throughout the season, ensuring a continuous supply for the market. In greenhouse production, the lower leaves are sometimes removed, mainly for hygiene purposes as disease can strike where the humidity is highest. Otherwise the vines are allowed to grow naturally and become a jungle of hanging fruit.

In the backyard, however, where the season is shorter, indeterminates won’t reach the size of the greenhouse plants, but they do need serious staking, with a large cage or strong stakes. And this is where the reason for pinching out the “suckers” probably began. With secondary branches shooting off in all directions, there’d be a need for even more support. By restricting the plant to a main stem, it made sense and was much easier to train the plant. Consequently, the habit of sucker pinching took off and it continues today.

If you need to keep your indeterminate plants under control, go ahead and remove any secondary branches that aren’t required, but don’t feel it’s essential to remove them all. Some like to remove lower branches to improve airflow or keep leaves off the soil. Otherwise, the question is, does it really make any difference?

The answer is yes — sort of. If you leave the secondary stems on the plant, you’ll likely harvest far more tomatoes than you would if you removed them, except they might be a tad smaller than the ones from a plant that had the suckers removed.

So there you have it, to pinch or not to pinch the suckers? The choice is yours. You’ll still get tomatoes.

Monday, June 19, 2023

It’s a Numbers Game

Fertilizer is confusing, and no wonder. Shelves are stacked with more types of fertilizer than supplements in a health food store. All are in brightly coloured packaging adorned with pictures of gorgeous flowering plants and unblemished vegetables. 

There are fertilizers for tomatoes, ones for roses, another for perennials and so on. All you need to do is match the plant to the fertilizer, right? It couldn’t be easier, except if you grow roses, tomatoes, and dozens of other types of plants, you’ll soon have a full shopping cart. The truth is, you could get by with only one type of commercial fertilizer, or even none if it’s for the garden. By using compost and mulch there, you’d still be fertilizing, but as nature does it.

You’ll note packages of fertilizer always have three numbers. These represent the three main nutrients plants require — nitrogen, phosphorous, and potassium, noted as N-P-K. If the K is throwing you off, that’s because it comes from the scientific term, kalium. These numbers indicate the percentages of each element in the package or bottle. 10-15-10 means it contains 10% nitrogen, 15% phosphorus, and 10% potassium.

You might be wondering why there are so many different proportions listed, and why manufactures can’t agree on those proportions. Next time you’re shopping for fertilizer, ignore the glossy images that were shot in a studio and compare those numbers.

You’ll immediately see they differ from brand to brand even though they’re specified for the same type of plant. I’ve seen brands of fertilizer formulated for tomatoes with the numbers 6-12-12, 4-6-8, 8-24-8, and 18-18-21. No wonder the consumer is confused.

Now you might be wondering how they came up with the numbers in the first place. When plants were first analyzed, it was found they contained different proportions of these three nutrients. It was then assumed that each type of plant required fertilizer in the same proportion, except plants don’t use nutrients the same way at the same time as they’re growing. They take up what they need from the soil when they need it.

It’s much like going to the grocery store when you’re out of milk, butter, or eggs. You buy what you need rather than stuffing the refrigerator. A balanced fertilizer, that is one with equal percentages, say 5-5-5 or 10-10-10, is fine in most situations, but by juggling the numbers manufacturers were able to make their products appear unique. And that’s when marketing with numbers began. But do you really need all that fertilizer? If you’re growing in pots and planters, indoors or out, yes you will need it, as most soil-less mediums have little or no nutrients, unlike real soil.

In the garden it’s a different matter. Remember that middle number, the one representing the phosphorus percentage? The soil in this area began with a limestone base, and as it degraded over time we were left with plenty of phosphorous in the soil. Garden soil doesn’t need any extra. In fact, so much has been added waterways are being polluted by it. 

As for the last number representing potassium, it’s only likely to be deficient in light, sandy soils, not in the typical clay soils we have in our gardens. This leaves nitrogen, the first of the trio. Nitrogen does not stick around in soil, which is why we’re forever fertilizing lawns. By adding compost and mulch, nitrogen and other nutrients are returned to the soil as the organic material is broken down.

Bottom line: If your plants are growing poorly, fertilizer is rarely the solution, and too much can be deadly.Your pots and planters will need it, so use the fertilizer of your choice, ideally, one with a ratio corresponding to 3-1-2 that lists additional micronutrients. These are important and usually found in the fine print.

Finally, do heed the directions. Like soap powder in the washing machine, more is not better. 

Friday, June 9, 2023

Getting High With Plants

Away from marketing, trends begin simply because people decide that something is a great thing to do. In the world of plants and gardens, there are two that are prominent, and they are both connected to that unfortunately branded group, millennials, that is, those born in the years roughly spanning 1981 to 1996.

By all reports, this group is into plants and gardens in two specific ways — or both. One is the surge in backyard vegetable gardens, simply because they like to feed their young families with their own healthy produce. Wait, haven’t Generation X and baby boomers been doing that for ages? Yes, but the latter are tapering off a little as they reach the age when bodies are creaking as much as an old wheelbarrow. Many of that group are now moving into apartments and condos, leaving their gardens behind.

It’s in those new high-rises that are springing up like — okay, weeds — where the other trend is taking place. That is the growing of houseplants, particularly succulents. Succulents are especially popular because they’re easy to take care of. Little do these people know they’re also the gateway to larger, more exotic houseplants.

Next thing you know, these folks will be wanting to grow plants on their terraces and balconies. I can see it now — small shrubs, trees even, with masses of vines climbing and cascading over their multi-story building, just like at Bosco Verticale, a pair of residential towers in Milan, Italy. Instead of cold steel and glass, greenery flows over the whole exterior surface of the buildings.

But why not here? Sure, Milan has an enviable climate, but we could start with roof gardens. Now I don’t mean green roofs covered mainly in hardy ground covers. They’re fine and have their purpose, but I’m suggesting more. Roofs on these buildings are wasted space when they could be productive. There’s plenty of room for raised beds where the building occupants can grow their fruits and vegetables, or ornamental plants if they wish, maybe even a cutting garden, and plants for pollinators, of course.

But what about a real garden? This isn’t a new concept, and many have been installed. Some years ago in London, England, I ate at a restaurant located on the roof of a six-storey building that looked out on a beautifully landscaped garden. The garden held over seventy mature trees, including oak. It even had a stream and a pond complete with wandering flamingoes. Known as the Derry and Toms Roof Gardens, it was on the roof of the former department store by that name which opened in 1933, when the gardens were first installed.

That may be ambitious, but why not? We’re losing green space, not only because of suburban sprawl, but in our uptowns and downtowns where the word is intensification. In order for this to take place, many new building high-rises are built on land that previously held houses. Gardens at ground level vanished along with the homes. “Paved paradise” anyone?

There is a need for greenery, for people to be able to stay in touch with the natural world, evidenced by the trends above, and countless studies have shown the benefits. It reveals an inherent need to stay connected. For those older baby-boomers living in the same buildings, there’s nothing many would like better than to again have a garden they can tend. They’d be lining up to buy or rent, so what about it, planners, architects, builders, and developers? You can do it. 

Monday, June 5, 2023

Notes on Butterfly Plants

We like to see butterflies in our gardens, that is some butterflies, particularly bright, colorful butterflies like the monarch. It’s the caterpillars that we don’t like, the ones that feed on our plants. Luckily for the monarch, the caterpillar stage only feed on weeds, that is, they feed on milkweed, typically common milkweed (Asclepias syriaca), a plant that’s essential to the survival of the monarch butterfly.

It’s not a plant that’s typically grown in suburban gardens, although it would help reduce the decline of the monarch if there was a milkweed plant in every backyard. Since it’s not considered particularly attractive as an ornamental plant, it’s unlikely to happen, but A. syriaca is only one of a number of milkweed species that appeal to the monarch.

In my garden, I have swamp milkweed, which has narrower leaves than common milkweed and grows to about a meter and a half with lots of pink flowers. This species favours medium to wet soils and is well suited to a rain garden or low area, although it wasn’t troubled by last summer’s long dry spell in my garden.

I grew another milkweed species a couple of years back from seed, Asclepias curassavica, a tropical milkweed commonly known as blood flower. This was a pretty plant with showy red/orange flowers and a nice addition to the garden at the time, but it’s not hardy in this area, dying completely over winter. When grown in warmer regions to the south where it can be invasive, questions have been raised about its impact on the monarch. It can act as a host plant, but it’s believed the growth habit of producing new foliage throughout fall and winter can result in continuous breeding on the same plants, ultimately affecting the natural migration patterns of the monarch. They don’t feel the need to leave for Mexico as they should.

There have been calls for eradication of tropical milkweed, but research is still underway to determine the impact of removing a plant that regardless, does provide essential food. Since tropical milkweed can’t survive beyond fall, it’s presumably an acceptable annual plant for our gardens in the north.

Better still, there is another milkweed species we can grow that will attract and feed monarch butterflies. It’s not a major host plant for the monarch larvae, but the flowers provide essential nectar for the adults and it also attracts other butterflies, hence its common name, butterfly weed (can we stop calling them weeds?).

This species is Asclepius tuberosa and like the tropical milkweed, it has similar orange/red flowers. Better still it is hardy to zone 3, making it tough enough to easily survive winter here. Plant in full sun and it will grow in a bushy shape to about knee height. Once established this plant is drought tolerant thanks to a deep taproot. A deep tap root means it isn’t easily moved, so choose carefully when deciding where to place it. This is such a well-respected plant that the Perennial Plant association has chosen it as the 2017 Perennial Plant of the Year.

If you’d like to learn more about attracting monarchs and other butterflies into your garden, there’s an excellent book by local author Thelma Beaubien. It’s called Gardening for Butterflies: Attracting, rescuing and raising butterflies.

Wednesday, May 24, 2023

Two Four Time

This is it, the traditional spring planting time in this part of the world, but if you don’t get around to planting because of other exciting two four stuff, don’t worry. There’s plenty of time left for planting.

Once upon a time, most annuals were sold in tiny cell packs and it created an urgency to get them into the garden early to ensure they started growing, even though they wouldn’t budge until the soil warmed up. Now, with a trend towards larger, more mature plants in individual pots, timing is less critical.

Whether you plant this weekend or wait until early June, there is one thing that will help your flowers and vegetables when they have to face blazing hot summer days, and that’s mulch. In nature, there’s always mulch on the surface of the soil, usually in the form of a leafy layer.

Plants expect to be surrounded by mulch; bare soil is not normal. Covering soil conserves moisture, keeps down weeds, and if organic, it slowly adds nutrients to the soil as it breaks down. Over the years, I’ve used a variety of materials as mulch: leaves, manure, mushroom compost, wood chips, straw, shredded bark, and cocoa bean husks.

Anything that covers the soil surface while allowing moisture to penetrate does the trick. I’ll even use clippings from evergreen shrubs, and I always make use of my ornamental grasses crop. It does a fine job in the veggie garden. As they break down, they all help feed the soil, which is so important.

Wood chips or shredded bark are popular, especially on flower beds in front yard gardens. A few bags may be all you need, but if you’re a heavy user, consider ordering in bulk. When spreading mulch from four to eight centimetres deep, which is usually sufficient, a big bag will go a long way.

There has been a concern that as wood based mulches break down, they can deplete the nitrogen in the soil, but this only occurs in the uppermost layer and isn’t as much of a problem as was once believed.

As mulch slowly decomposes, nutrients and organic matter are absorbed, feeding the organisms in the soil. This is a natural process, but it is far more complex than it appears, especially to anyone who dismisses soil as dirt — dirt is what you get on your pants after sitting in soil.

Soil is not inert brown stuff, devoid of life, although it may well be if it’s been regularly doused with chemical fertilizers. It is teaming with an incredible number of life forms, each of which has a role to play. Worms and soil insects are easy to spot, but it’s what we don’t see that’s tremendously important:  microscopic insects, fungi, bacteria (good and bad) all play a role. They form symbiotic relationships with each other and with the roots of plants and trees, processing organic matter and minerals, converting them into nutrients in a form that plants can use.

Healthy soil is essential, the source of the life above ground that we can see. As you plant like crazy over the next few weeks, give a thought to what’s going on below — and spread the mulch.

Thursday, April 27, 2023

You don’t need a license to grow trilliums

I can’t say the now defunct design of the new Ontario licence plates concerned me particularly, but it was nice to see the trillium featured on them. I also liked the reference to gardening with the statement that Ontario is a place to grow. The trillium has been Ontario's floral emblem since 1937, and as I’m sure everyone knows, that funny little symbol with three points does represent our provincial flower.

The trillium is also the state wildflower of Ohio, but they don’t honor it the way we do in Ontario. During World War I, the Ottawa Horticultural Society suggested the gentle white trillium should be planted on the graves of Canadian soldiers to signify the homeland left behind, however it was never pursued.

I have a trillium flowering in my garden now, despite suggestions circulating that anyone with a trillium must have plucked it from the wild and in doing so broke the law.

I’m happy to report that I have not, nor am I likely to end up in jail or even be arrested. That’s because it is not against the law to pick or remove trilliums from woodland, unless of course the location is private land. With a slow spring this year, trillium blooms are peaking, or may have passed further south, after lighting up the forest floor. With so many in bloom it’s not surprising that someone is tempted to scoop a few blooms, or even dig up the whole plant.

Although not protected by law perhaps they should be, as should all our precious wildflowers. Picking the trillium for its flower causes damage to the leaves and stems that are essential to future growth. Trilliums don’t transplant at all well from a woodland, and besides harming the plants, it removes the enjoyment for others.

Fortunately, you can grow them in your own garden because they can be purchased from many nurseries that specialize in, and propagate, wildflowers. The trillium you most likely see growing everywhere is Trillium grandiflorum, although according to Ontario Parks, there are another four species.  There’s the red trillium, the painted trillium, the drooping trillium (listed as at risk) and the nodding trillium — I’m not sure I’d be able to tell the difference between the drooping and the nodding.

The red trillium is Trillium erectum, and it’s easy to spot when it pops up in the middle of a patch of white ones. It would even be easy to find one in the dark. Unlike the white variety, which has no fragrance, the red one has the delightful fragrance of day-old roadkill, perfectly designed to attract pollinating flies — and another valuable pollinator plant to add to the garden.

Despite being called the red trillium, the flower has a slightly more burgundy look about it. In fact, deep in the forest there have been reports of ones with slight variations in colour, even orange — I’m still looking. The common name for the red trillium is ‘wake robin’, said to have referred initially to the European robin. Both it and our native robin have similar colouring, and I’m only guessing, but as the breast colour of both birds leans toward orange rather than red, maybe an orange trillium was more common century or so ago.

There is another species of red trillium I’d like to try growing in my garden and that’s Trillium chloropetalum, the giant wake robin, and it’s a beauty, growing as high as forty-five centimetres high (18 inches). Although native to California, it is a zone six plant, making it just about hardy enough to grow here.

Wait, there are more. About fifty other species of trillium have been recorded, mostly in North America, though generally further south. So, do watch out for any unique species, but no picking. Unlike the new license plates, they’re not collectors’ items.

Thursday, April 20, 2023

Bees Above Are Buzzing

Numerous studies in many parts of the world are showing a dramatic fall in insect numbers. They’re essential for agriculture, and essential in a garden where fruiting plants are grown, including our beloved tomatoes. Habitat loss, monoculture farming, and the widespread use of insecticides are among the reasons for this decline.

For a long time, many home gardens were unwelcoming to pollinators. We had monoculture lawns, heavily mulched and tidy flower beds, and until the pesticide act in 2008, there was regular spritzing and spraying of everything in sight, indiscriminately wiping out beneficent insects. This didn’t end pesticide use, only the formulas changed to comply with the law. Shelves are still filled with sprays and powders to rid gardens of pests, and beneficial insects can be killed just as effectively as before.

One of these important insects that specifically needs our help is the humble bee. Not including the honey bee, a non-native species, there are over 800 distinct types throughout the country, 400 of which can be found in Ontario.

But if it's honey you want, we rely on the honey bee. Did you know that a good part of your honey may have come from insect poop. Yes, you heard that right, and I apologise if you’re drizzling honey on your cereal right now. A study of the DNA in honey carried out by Noah Wilson-Rich, an entomologist who founded The Best Bees Company, revealed that fact and other valuable information. The study sampled urban hives in major cities across the US and the preliminary results are surprising.

We naturally assume that honey bees are busy collecting nectar and pollen from flowers, and we know they do because we watch them doing it. It’s a biased perception, however, as it’s easy to see the plants that bees are visiting in our gardens. We’ve not been paying attention to what they do at higher altitudes, and that’s one of the major discoveries that was made when the DNA in honey was studied.

The main sources of sugar in the honey tested did not come from wildflowers, but from trees, and not only from the blossoms; it also came from the excretions of sapsucking insects, particularly aphids, those pesky critters that drive gardeners wild when they find them munching away on plants.

What goes in one end of a hungry aphid is the sap that the plant depends on to grow and flourish. Too many aphids and the plant can die. It’s what comes out of the other end of the aphid that attracts the bees. It’s a sweet, sticky substance called honeydew. Besides nectar from flowers, honeybees are slurping up honeydew, and there’s often plenty of it. We might see only a few aphids on plants in our gardens; up in the treetops there can be tremendous numbers — easy picking for bees, and there’s even more food available when a tree is in bloom, far more than in a garden below.

Whether from nectar or from honeydew, the study determined that 75% of the sugar collected by honeybees came from trees and not from wildflowers, especially in an urban setting. Although more native wildflowers than ever are being introduced into urban gardens to benefit pollinators, there’s often a far wider range than is present in a natural, rural area. In Boston, where interest in urban beekeeping has grown dramatically, the honey sampled contained the DNA of 411 plant species. Because of this larger diversity of plants, the hives there appeared to be healthier and more productive than rural ones.

Another discovery made by the researchers was regarding the types of trees and flowers the honeybees preferred. Surprisingly, the flowers and trees favoured by them are not necessarily native ones. Honey bees don’t seem to care where lunch comes from. Even though coniferous trees are predominant in Seattle, the bees there favoured non-native linden and cypress trees.

Preferences varied from city to city because of the popularity of particular plants in a specific region. For instance, in New York, where even luxury hotels keep rooftop hives, the top three plants were locust and linden trees, and the flowers of sedum. In Portland, Oregon, known as the city of roses, no surprise that roses were in the top three along with begonias and sweet chestnut trees.

In San Francisco, where non-native eucalyptus trees have become an invasive species, there’s currently a debate going on whether to fell them or give them protection. The honeybees are not fussy. They’re such generalists, they don’t care that the trees are from Australia. They love them. Making up their top three favourites there are pine trees and rosemary.

Next time you hear buzzing in your garden, remember to look up, way up.