For Faster Coverage, Mix Annual and Perennial Vines


Let annual climbers like this morning glory (Ipomoea tricolor ‘Heavenly Blue’) fill in while you’re waiting for your permanent climbing plants to start to take their place. Source:

Most perennial vines, that is herbaceous and woody climbing plants such as clematis, honeysuckle, or Boston ivy, grow slowly at first and can take 3 or 4 years (even longer in the case of climbing hydrangea, Hydrangea anomala petiolaris) before really giving you the effect you’re looking for.

That being the case, while you’re waiting for them to perform, why not sow annual vines between the permanent ones: morning glories, sweet peas, runner beans, thunbergias, etc.? Annuals will reach their full height (often 10 feet/3 m or more) during a single summer. When the permanent vines reach an interesting height and size, just stop sowing the annuals!


Can You Plant Forgotten Tulip Bulbs in the Spring?

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Source: & &

Question: Help! I just discovered two bags of tulip bulbs that I forgot to plant in the fall. Can I still plant them this spring?

P. Carmichael

Answer: You wrote me on March 17th. Essentially, therefore, in early spring (at least in the northern hemisphere), while you would normally plant tulip bulbs in the fall (September, October or November),

The usual growth cycle for a tulip is to produce roots in the fall in cool soil and grow under the snow all winter to be ready to bloom early in the spring. After blooming, the plant goes dormant for the summer before reawakening in the fall with the return of cool soil temperatures. Thus, planting tulip bulbs in the spring is not just asking it to make a minor change in its growth cycle, but throws it off its schedule by a good half year!

Had you caught the error earlier, say in December or early January, you could have potted the bulbs up and forced them (gotten the bulbs to bloom off-season in pots) in a cold room or barely heated garage, but for that, you’d need to offer about 14 weeks of cold. That seems unlikely at this late date.

The most logical thing to do with tulip bulbs found unplanted in the spring is to compost them. There is a season for everything and you have simply missed the bulb planting window this year.

Nevertheless, there may be one final way of “saving” them.

Where Were They Stored?

At least, you might be able to save them if you stored the bulbs indoors. If you’ve just found them in a shed or unheated garage in a climate where the winter is cold, that is, a spot where they will have undergone freezing temperatures, there is nothing you can do. Bulbs that freeze completely before they have formed roots will be dead. Touch them and see: they’ll be soft and rotting.

Planting Fall Bulbs in the Spring


If tulip bulbs are still alive in the spring, they’ll likely be trying desperately to sprout. Source:

If you did store them in your home, in a heated garage or in some other frost-free spot, there is still a (very) slight bit of hope, especially if the bulbs still look plump and healthy. By this time of year, they’ll probably show growth at the tip of the bulb, a sign they really want to get growing!

Plant these bulbs in the garden as soon as the ground has thawed: they’ll appreciate the still-cold soil. It’s very unlikely they’ll bloom this spring, however: the embryonic flower, hidden inside the bulb at the time of purchase, is probably dead by now. However, at least they should be able to produce leaves. And thanks to their leaves, the bulbs will be able to capture and store solar energy and thus regain their strength for growth the following spring.

At least, that’s the theory. The bad news is that most hybrid tulips, including the ever-so-popular Triumph tulips, are not very perennial. They were bred to supply one single spectacular show of flowers, then deteriorate. They’ll therefore have a lot of difficulty with this method. You may see them produce leaves next year, but it’s quite likely they’ll simply never bloom. Botanical tulips are tougher and will likely recover and bloom again. If not next spring, the following one. Also, most other spring-flowering bulbs (narcissi, hyacinths, small bulbs, etc.) are also more perennial than hybrid tulips and thus more likely to eventually recover from such an affront.

Don’t Wait Until Fall

It is not a good idea to hold on to your tulip bulbs even longer, until next fall, thinking to plant them at the “right season.” Bulbs aren’t seeds, many of which can be stored for years and still germinate. Bulbs continue to carry out respiration, albeit at a reduced rate, throughout their dormancy. In delaying their planting by a full year, you’ll have effectively killed them.

You can abuse bulbs to quite an amazing degree, but planting them a full year later than you should is really asking them just too much!20180322A, &

A Laidback Gardener’s Guide to Planting in Dry Shade


Yes, you can have a beautiful garden in the shade of tall trees. You just have to know how to start the plants off on the right foot! Source:

Shade has a very bad reputation among gardeners and they blame it for the general lack of success they have gardening in wooded areas. Of course, it’s true that you can’t grow just any plant in shade (vegetables, for example, loathe it), but there are in fact lots of plants that will grow perfectly well in shade. I mean plain shade, such as on the north side of a building or under a pergola. Not the shade of trees. Because under trees, the situation is very different.

You see, the real problem of gardening under trees is not so much the shade itself (not if you choose the right plants) as the presence of so many tree roots. These roots dry out the soil, leaving it in a state of perpetual drought, and also deplete most of its minerals while they’re at it. This is called root competition. Some trees (maples, spruces, pines, willows, sweetgums, birches, etc.) are worse than others, with root systems that literally skim the soil surface or even rise above it and really suck all the goodness out. And make digging hell too! But just about any tree, even the so-called deep-rooted ones, is going to have plenty of roots in the top foot (30 cm) of soil. This combination of conditions—shade and root competition—is what is known as dry shade.

No matter how many complaints you may hear about dry shade, it isn’t particularly hard to cope with. You just have to know what to do. Here is my technique:


Illustrations by Claire Tourigny, taken from the book Les 1500 trucs du jardinier paresseux

1. Dig big. You need a big planting hole, as deep as the new plant’s root system and three to four times as wide. The wider the hole, the slower tree roots will be in coming back. So a big hole gives your plant a chance to settle in before the competition arrives.


2. Cut roots if necessary. After all, otherwise you won’t be able to dig at all! You’ll need more than a shovel: pruning shears, a hand saw, maybe an axe. Sure, if you hit a big root, move the hole over a bit and start anew, but otherwise feel free to chop the hell out of any secondary roots you run into. Don’t worry that you’ll be harming the tree. A healthy tree can lose a third of its roots in one year and still be in fine shape. It will simply respond to root pruning by growing abundant new ones.

20180321C.jpg3. Line the hole with newspaper (7 to 10 sheets). If you have not access to newspaper, used cardboard. Do this for the same reason as point 1 above: to keep the tree roots from moving in before your plant has settled in. Do not use landscape fabric! You want a temporary barrier that will decompose and disappear over time so your plant’s roots can expand. (And landscape fabric will not keep tree roots out for long at any rate: they’re very tenacious!) Make sure you cut off or fold down any part of the newspaper sticking above the ground; otherwise it will act as a wick and dry the soil out further. An added plus is that when a paper or cardboard barrier decomposes, it turns into … compost! So it feeds your plant as it disappears, usually within 12 to 18 months.

20180321G.jpg4. Plant only plants that tolerate dry shade. Why put in a sun-loving plant like a peony? It will only be miserable. Or a moisture-living plant like an astilbe? It will out-and-out die. Try hostas, epimediums, Solomon’s seals, bigroot geraniums, hellebores, wild gingers, ajugas, even many ferns (many are much more drought resistant than they are given credit for). The list of plants that can tolerate dry shade is surprisingly long! Check out my book, Making the Most of Shade for tons of suggestions.

20180321D.jpg5. Plant only large, fairly mature plants. This is more important than you think! Young plants, even those that are reputedly tolerant of dry shade, will have a very difficult time settling down in an area that will soon be invaded by tree roots. Even if they do survive, the competition is such that they’ll take forever to reach their full size. But a mature plant, with its large mass of dense roots, will be able to withstand the coming assault. Plus you get that “well-established garden” look right from the start!

6. Backfill with a mix of compost and the original soil, then water well. But you already knew that, so skip on to the next point.

7. Give your plantings extra care the first year. You probably already know that too, but I want to insist on it. Any new plant needs extra care at first and plants that will eventually be drought-stressed by surrounding tree roots, more than most. You don’t need to keep them soaking in water, but do check weekly and water if needed. The old “finger in the soil down to the second joint” method still gives you the best moisture meter ever! If the soil feels moist, don’t water. If it feels dry, do water. And watering is the main care new plants need at this point. Dry shade plants, practically by definition, don’t need particularly good soil or even much fertilizer, but they do need moisture until they are thoroughly established. Then you can bring on the dry conditions and let them grow on their own.

8. Finally, mulch is always good in a dry shade garden. Always!

That’s it! When you apply the right techniques, creating a beautiful garden in dry shade is a cinch.20180321A

Honey, They Shrunk the Hydrangea!


Smooth hydrangea Invincibelle Wee White (Hydrangea arborescens ‘NCHA5’). Source:

In temperate climates, ‘Annabelle’ smooth hydrangea (Hydrangea arborescens ‘Annabelle’) is among the most popular landscape shrubs. You simply can’t miss its big pompons of pure white flowers from midsummer through early fall. In my neighborhood alone, I’m sure at least one house out of five features this shrub. And it’s been around for quite a while. ‘Annabelle’ was first discovered in the town of Anna, Illinois (whence the name Annabelle) in 1960 and was first made available to gardeners starting in 1962.

Despite its popularity, ‘Annabelle’ is not without its flaws and the one that annoys gardeners the most is that its stems, rather thin, often flop over under the weight of the huge ball of sterile flowers. But there is now an easy solution to this problem: the brand-new cultivar ‘NCHA5’, sold under the trade name Invincibelle Wee White®.

It is essentially a dwarf ‘Annabelle’, about half its height! At only 1 to 2 ½ feet (30 to 70 cm) tall, compared to 3 to 5 feet (90 to 150 cm) for ‘Annabelle’, but with a pompon of flowers almost as large, its shorter stems are better able to stand upright, even under torrential summer rains. In addition, while ‘Annabelle’ normally only produces one crop of flowers, Invincibelle Wee White is an rebloomer, flowering on and on, thus extending the season of interest right through to the end of fall. Another difference: the flowers age to pink and green as they mature while those of ‘Annabelle’ go straight to green.

Because of its smaller size, Invincibelle Wee White is an excellent choice for borders and container gardens and is also useful in mass plantings. As with ‘Annabelle’, its winter effect is also interesting, although its flowers are dry by then, they still hold on to the plant. Like ‘Annabelle’, Invincibelle hydrangea Wee White also makes an excellent fresh or dried cut flower.

Easy to Grow

Invincibelle Wee White is as easy to cultivate as its parent.

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Smooth hydrangea Invincibelle Wee White. Source:

Give this North American native full sun or partial shade and any relatively rich and well-drained soil. It can be pruned back by about one third in the spring just as new buds start to appear. This will stimulate maximum bloom.

It’s not a very greedy plant and will get along fine with no fertilizer unless your soil is extremely poor. If you want to fertilize it, do so lightly with an all-purpose one. Avoid fertilizers rich in nitrogen, as they tend to encourage foliage growth over flowering.

Finally, Invincibelle Wee White is extremely hardy, to zone 3, tolerating -40˚ F (-40˚ C) with aplomb.

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Leaves sealed together by the hydrangea leaf-tier, an insect that only attacks smooth hydrangeas (Hydrangea arborescens). Source:

No smooth hydrangea (H. arborescens) is fully resistant to the hydrangea leaf-tier, an insect that seals the leaves at the end of the stems together and can cause flowering to partially abort. But since Invincibelle Wee White is a rebloomer, you can simply cut off the offending stem tips and it will soon be back in flower. Since there is only one generation of leaf-tier a year, it won’t attack again.

20180320C Direct Gardening Association.jpegAward Winner

Invincibelle Wee White received the prestigious Green Thumb Award from the Direct Gardening Association as one of the best new horticultural introductions of 2018.


Although new for 2018, Invincibelle Wee White is apparently already available throughout Canada and the United States. I assume it will reach Europe in a year or so.20180320A

Plastic Bottles Make Great Mini-greenhouses!


Easy-peasy mini greenhouses! Source:

In spring, when trays of seedlings and cuttings start to fill our homes, transparent mini-greenhouses are ideal for covering the soon-to-be plants. They help create the famous “greenhouse effect” young plants so love, keeping both seedlings and cuttings in warmth and high humidity … just what they need for a good start in life. You can, of course, buy plastic domes specifically designed for this purpose: every garden center sells them, as do seed catalogs, but you may already have everything you need at home … in the form of plastic bottles: water bottles, juice bottles, soft drink bottles, etc.

If you cut a plastic bottle in half widthwise, you will get not one, but two mini-greenhouses: the base, inverted, and the top. (Yes, do leave the cap on: you’re striving for high humidity, after all!)

Small bottles, like individual portion water bottles, are fine for small pots. 2-liter bottles will cover larger ones. And you can find even larger bottles if you look a bit.

Note that these mini-greenhouses are only used for a short time, just to get seeds and cuttings stared. Once seedlings germinate and cuttings are rooted, you don’t need them anymore, as young plants have to adapt to real-life conditions, including less humid air. So the fact that these home-made coverings are not that tall is not a problem: you’ll have removed them long before the young plants reach their top.

Making the Cut

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You can cut the bottle with a knife or scissors. Source: papersculputure,

To cut a plastic bottle in two, use a sharp knife or utility knife (X-Acto) to pierce the initial hole. You can continue cutting all around the bottle with the same knife if you want, many people prefer finishing with scissors. They’re a little less hazardous for your fingers! Just experiment to find out what works best for you.

After use, clean your mini-greenhouses by wiping off any soil that sticks to them and stack them for use the following year.

Best of luck with all your seedlings and cuttings!20180319A

How to Make Your Own Paper Pots


You can use a pot-making tool to produce hundreds of seedling pots. Source:

If you’re still reading the paper edition of the local newspaper or if you regularly receive ads on newsprint in your mailbox, you can make pots for seed starting for next to nothing.

There is even a tool—called a Potmaker, Pot Maker or Paper Potter, depending on the manufacturer—designed specifically for this purpose. Here’s how it works:

This video by Lee Valley Tools shows how to use a Potmaker.

Simply cut a sheet of newspaper into strips of about 3 to 4 inches (8 to 10 cm) in width and wrap a strip around the mold, letting part hang over the bottom. The paper should fit fairly tightly, but not so much it will be hard to remove afterwards. Next, fold the excess paper at the bottom over the base of the mold, then firmly press it into the mold base, turning left and right. Remove the paper pot from the mold … and that’s it! You have a perfect little pot for your seedlings: all that remains to do is to fill it with sowing mix!

This is not a tool I’ve been seeing in local garden centers, but you’ll find it readily on the Internet, notably at Lee Valley Tools in Canada and the United States and on in Europe.

You Don’t Have a Potmaker?

You don’t have a manufactured pot-making tool or you find it too expensive?

(But think the latter over. You get a very quick return on your investment: after just one year of use, the average gardener who sows seeds indoors will have saved more than the price of the tool on plastic and peat pots they didn’t have to buy.)


Wine bottle used as a pot maker. Source:

You can make paper pots using household objects as a mold. A wine bottle (one with a depressed base would be especially interesting), a can or any other cylindrical object of appropriate width will do. Just wrap the strip of newspaper around the base of your tool and fold it in at the bottom, pressing firmly. These pots are not as solid as those made using a pot-making tool and you may need to use a bit of Scotch tape to keep them from unraveling.

No, Newspaper is Not Toxic!

Do I even need to mention that today’s newsprint does not contain toxic ink, not even the color pages? That’s one of those horticultural myths that will not die! Yes, you can use newspaper in organic gardening. In fact, it’s probably the very best way to recycle it!

There you go! Biodegradable pots that are essentially free, are highly useful for seedlings and even recycle paper in an environmentally friendly way … and you made them yourself!

Repotting Boot Camp

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This pot is nearly full of roots: definitely time to repot the plant! Source: Conrad Nutschan, Wikimedia Commons

Hey, it ain’t rocket science, but when you grow houseplants, you need to repot them from time to time. And if you’re going to repot, you might as well do it right! Here’s what to do!

When and How Often?

For most plants, an annual repotting is wise (see Why Repot Houseplants?), preferably in the spring, although summer and fall are also quite acceptable. Young plants that grow quickly (newly rooted cuttings, for example) may well need two repottings per year, moving them into larger pots each time. Plants that are mature and scarcely growing, such as indoor trees, as well as plants that grow very slowly, such as cacti and succulents, however, may stay in their pot for longer periods, up to 4–7 years some cases.

Getting Your Pots in a Row

Start by gathering the tools and products you’ll need. (There’s nothing more annoying than interrupting a repotting session to run off to the garden center in search of a missing item … unless it’s to run off to the garden center a second time just a few minutes later when you realize something else is missing!)

Here are some things you will need: pots, potting soil, a digging tool of some sort (a spoon borrowed from the kitchen will often do), a watering can, and a bucket or large bowl. And you may need the following: fertilizer, mycorrhizal fungi, horticultural charcoal, a sharp knife or pruning shears.

Most gardeners already have a ready supply of recycled pots: just clean one up thoroughly before reuse. Source:

You’ll need a pot one or two sizes larger than the original pot (that’s about 1–2 inches/2–5 cm) for small and medium-sized plants. For plants in large pots (12 inches/30 cm and up), consider a pot 3 or 4 inches (8–10 cm) larger. Remember any pot you use must have one or more drainage holes; if not, declare it officially not a pot, but a cachepot!

In general, tropical plants (African violets, spider plants, dracaenas, philodendrons, etc.) prefer a pot with impermeable sides, such as a plastic pot, as they dry out a bit more slowly. Cacti and succulents, on the other hand, do better in a pot that “breathes” such as terra cotta, as they actually prefer their growing mix to dry out more rapidly. That said, the material from which a is made a very minor detail. You can grow almost any plant in any pot (as long as it has a drainage hole, of course!).

Use the potting mix of your choice. Source:

Any packaged mix labeled as potting mix or potting soil will do. African violet potting soil is just standard potting soil with a fancier name. There are more aerated soil mixes for orchids and better-drained potting soil blends for cacti and succulents. Never use garden soil indoors: it may contain insects, disease spores and other unwanted hitchhikers and will almost certainly turn hard as rock after 2 or 3 waterings. I prefer soils that already contain mycorrhizae.

Off You Go

Prepare the soil first. Pour some into a bucket or bowl and add any ingredients you think are lacking. They can include:

  • Fertilizer: commercial potting soils usually already contain a 2- to 3-month supply of fertilizer; if not add the slow-release fertilizer of your choice to the potting mix. Never exceed the recommended dose of fertilizer, however: it will burn your plant’s roots and can even kill it. Remember: too much fertilizer is much worse than not enough!
  • Mycorrhizae: add them if your packaged soil doesn’t contain any. The vast majority of plants grow best when they are in contact with these beneficial fungi. Again, apply as recommended on the product label, but don’t worry if you add too much: it’s harmless to plant roots.
  • Horticultural Charcoal: an interesting addition if you expect the plant will be spending many years in its new pot (for example, a big plant you have no intention of ever repotting again!). Unlike other products added to potting soil to lighten it, like perlite and vermiculite, it doesn’t compact or condense over time (or at least, only very, very little), so it helps the mix maintain good structure for a longer time. Just add about 1/8 to 1/4 cup horticultural charcoal per 2 cups of mix.

Now add water to your soil mix. Yes, before you pot up. Modern soils are usually based on peat, coir, or bark, all products that repel water when very dry. So pour tepid water into the mix and stir it in with a spoon. The physical action of stirring miraculously makes the mix easy to moisten! Add enough water that the mix reaches a barely moist state. If you’ve gone too far and it is soaking wet, let the excess water drain out.


Knock part of the old mix off with a finger or stick. Source: Claire Tourigny, from the book Les 1500 Trucs du jardinier paresseux

Now, remove the plant from its pot (see How to Remove a Pot with Minimal Damage), and with a finger, spoon, pencil or chopstick, knock off about 1/3 of the old potting mix, going all around and underneath the root ball. Make especially sure to knock off some surface soil because it is usually the part most contaminated in mineral salts.


If there is a mass of roots at the bottom of the pot, just cut it off. Source:

If there is a mass of roots circling the bottom of the pot, slice them off with a knife or pruning shears. Just gather your courage and cut away! Those long roots were meant to anchor the plant in the ground in an outdoor setting; they are useless to a plant that grows in a pot and removing them will not harm the plant.

page 217 cutting roots

Cut off any encircling roots. Source: Houseplant for Dummies by Larry Hodgson

If there are roots entirely circling the root ball, cut them off too or they may come to strangle the plant over time.


Put a simple filter over the drainage hole: no need for gravel or pot shards. Photo:

Placing a so-called drainage layer of gravel or pot shards on the bottom of the pot is just a waste of time, effort and space. (See Gardening Myth: Houseplants Need a Drainage Layer.) However, you can place a piece of newsprint, paper towel, coffee filter, geotextile or mosquito net over the drainage holes and thus prevent the soil from washing out the first few times you water. Or don’t! If you don’t mind a few particles of soil dripping into your saucer, it isn’t worthwhile.


Don’t fill with potting mix right to the top: you need to leave as space into which you can fill with water when you’re rehydrating your plant. Source: Claire Tourigny, from the book Les 1500 Trucs du jardinier paresseux

Now pour enough of your pre-moistened potting mix into the bottom of the pot to raise the plant to the desired level. (The top of the root ball should be about level with the lower part of the pot’s rim.) Center the plant in the pot, then add potting soil around the root ball. Tamp lightly with your fingers. Finally, water well.

Most freshly potted plants can go right back to their original location. If the plant is growing in full sun, however, it would be wise to put it in a place a little less well illuminated for a few days, the time it takes to recover from transplanting shock.

That’s it: all it takes to successfully repot a houseplant. Get to it!