Tag Archive | Pruning

Enjoy Beautiful Clematis

41e8e1011b15529bfcc1bc2d9df3806aA clematis in full bloom can take your breath away. Who hasn’t erected a trellis with the dream of seeing it covered with vibrant red or purple flowers in late spring? But how do you get your clematis to grow as lush and beautiful as you see in magazines or in your neighbor’s garden?

First, you need to know your vine so you can understand the proper pruning that it needs. Your clematis will survive, and even bloom, with no pruning. But with the right pruning, it’ll grow and bloom more vigorously.

Before that, though, let’s understand how to plant for success.

  1. Start with the soil. It is true that clematis prefer slightly alkaline soil. If a soil test* tells you that yours is on the acid side, your vines will benefit from some agricultural lime. But if it’s already alkaline, don’t add lime — you can overdo it. A pH of 7 to 7.5 is just right. Dig the hole 18 in. deep and wide, and work in lots of moisture-holding compost. Set young plants deeply so the first two sets of leaf nodes will be underground. This encourages plants to send up more stems so you’ll have a thicker plant.
  2. Mulching matters! “Head in the sun, feet in the shade” is old clematis advice. However, a 4-in. layer of mulch keeps the roots cool and moist just as well as shade does. To prevent stem rot, keep the mulch about 8 in. from the stems.
  3. The best place to prune a stem is just above two strong buds — where two leaves were growing the previous year. These buds will quickly develop into new vines. Don’t worry about making angled cuts — it’s not necessary.
  4. Recognize disease quickly! Clematis wilt is easy to spot: a portion of your vine wilts quickly, often just as the plant starts to bloom. Wilt is caused by a fungus that enters the stem, usually just above the soil line. There is no cure other than to cut the entire stem to the ground and dispose of it in the trash. Do this as soon as you notice the wilt. That’ll prevent spores from moving to other stems. Systemic fungicides can help prevent wilt from spreading to healthy stems and the rest of the plant will usually survive, providing there are enough other healthy stems. That’s another reason to plant clematis deeply: if a stem becomes infected and has to be removed, more will come from the base to replace it. Cultivars that have proven resistant to wilt include ‘The President’, ‘Ville de Lyon’, Nelly Moser’, ‘Betty Corning’, and ‘Jackmanii’.
  5. Clematis like to be well fed but not overfed. Feed them once a year right after pruning with an all-purpose, granulated fertilizer, such as a 10-10-10.
  6. Choose the right trellis. Clematis climb by twisting petioles, or leaf stems. The vine 3670663326_9f7e6f0a29_bitself does not twine. So, if your structure is too large, the leaf can’t wrap around it. Anything over 3/4 in. in diameter is too large for a leaf to grasp. Nylon fishing line is a great way to get a clematis to climb a light pole or arbor post. Put a knot every foot or so to keep the vine from sliding.

Pruning Pointers

So, how do you prune a clematis? Timing is important: don’t prune in the fall. It will encourage the plant to emerge from dormancy at the first hint of a warm day — which could be in January and your plant will die. No matter where you live, let your clematis stay dormant until spring.

Before you start cutting, you’ll need to know which pruning group your clematis is in: A, B, or C. If you don’t know, just watch it for a year. First pay attention to when it blooms. Second, notice whether it blooms on woody stems that grew last year and then survived the winter (old wood) or green, flexible stems that came from a main stem this year (new wood). Once you know this, you can usually put your clematis into group A, B, or C.

The University of Maryland Extension has created a wonderful little brochure that explains exactly how to prune each of the categories of clematis to ensure the best results.

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Now that you know these secrets, you no longer have to wonder how to get those spectacular flowers you see in photos — you’ll be enjoying your own!

 

*Not currently testing your soil before planting? Shame on you! To ensure the best success for your gardens, it’s important to know if your soil is helping or hindering your efforts. Read our earlier blog post on doing soil testing here.

 

 

 

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Pruning Water Sprouts

by Sharon Morrisey, Milwaukee County consumer horticulture agent

apple-watersproutsAs a general rule, pruning of woody landscape plants should not be done in midsummer. The one exception is water sprouts on fruit trees, particularly apples and crabapples. Both are in the genus MalusĀ and have a greater tendency to produce water sprouts than most other genera. Water sprouts form in response to pruning out large, diameter branches.

hqdefaultIt has been shown that if the removal of water sprouts is delayed until late July or early August, fewer new water sprouts will form. If pruned out in early spring when all other pruning is being done, more water sprouts will be stimulated and a vicious cycle begun.

Water sprouts are branches that grow straight up from a larger-diameter branch. They grow very quickly and arise from latent buds buried deep inside the larger branch. The sprouts push through the outer layers of wood and bark.

As they grow taller and thicker, they become top heavy. Since they have no real connection of the branch, summer and winter storms can blow them over, and in the process, break the branch they are growing on. These sprouts also look awkward and out of place.

To avoid having to prune out large branches, begin developing the structure of trees when they are young so you remove only small branches.

Pruning Rule Breakers

rhododendron-245633_960_720Rhododendrons, unlike most shrubs, have no painless window for pruning. They start forming the buds for next year’s flowers before this year’s have even opened, and by the time bloom season is done, those buds are well advanced.

It’s difficult emotionally to cut off any of next year’s flowers, but if you continually avoid pruning, you may be even more devastated. In fact, you could end up having to cut the rhododendrons to the ground and start all over again.

Pruning rhododendrons requires imagination as well as sharp sheers. Dr. Richard Lighty, the director of the Mount Cuba Center for the Study of Piedmont Flora in Greenville, Delaware, advises that you try to visualize what the shrub should look like. Reach your goal by critically selecting strong outer branches that, when pruned back, will expose smaller inner branches in the right position to fill in. Once exposed to light, these inner branches will begin to grow.Rhododendron-pruning-outline-diagram1

As the flowers fade, trim no more than 15 to 20 inches off the strong branches. Where should you prune? Where the strong branch is near the tip of an inner branch that has a whorl of glossy leaves surrounding the buds, your signal that the inner branch is healthy. If the shrubs are still too big, reprune in two years.

To make sure the plant has stored enough food that it can easily handle pruning, fertilize in late fall the year before you intend to prune. If you fertilize after pruning, it will put out long, leggy growth.

Although it is better to stay on top of your regular pruning chores, rhododendrons can be cut down to 12 to 15 inches from the ground if necessary. The plants have buds at their base that will generally send up new shoots. But, as I learned, there won’t be any flowers for two to three years.

Shearing is not Pruning

This time of year, we’re preparing for winter and many folks are doing some Fall pruning. Do you say you’re grabbing your shears

Ficus benjamina (formally sheared)

Ficus benjamina (formally sheared)

or your pruners? There is a difference between pruning and shearing.

Pruning means cutting off a part of a living plant, and covers everything from snipping a twig to reaching deep inside a tree canopy and sawing off a major branch. Shearing is a particular kind of pruning, one in which only branch tips are cut, and they are cut as a group rather than individually.

The goal of shearing is to force lots of small outer branches while creating a smooth outline. The result — if it is successful — is that the sheared plant loses it’s natural identity and becomes a formal shape.

Creating a box hedge topiary by hand

Creating a box hedge topiary by hand

The most common example of the technique is the flat-faced wall of a sheared hedge, but people also shear plants into mounds, pyramids, graduated balls on sticks, or (in a few extreme cases) things like chess pieces and leaping dogs.

Shearing at the simple hedge level seems as thought it should be easy; just hold the shears at the proper angle and clip away. In fact, it takes patience, practice — and strong arms — to see where you need to cut and then do the cutting properly.

Electric hedge trimmers promise to relieve you of much of the work, and they do make it go faster. But they are heavier than hand shears, their speed increases the chance of mistakes, and they have a regrettable tendency to tear everything they touch instead of cutting cleanly.

Pruners

Pruners come in two basic styles: anvil and bypass. With anvil pruners you have only one sharp cutting blade, which closes against a dull bed (the anvil) to sever whatever. Bypass types are more like scissors, with two sharp blades, one of which secures the branch while the other moves past it, cutting as it goes.

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Anvil Pruners

Anvil pruners cannot be brought as close to the cut as bypass types, but they do have two advantages: only one sharp blade means only one blade to sharpen, and the mechanism does give a bit more leverage. Though this can make a difference if you want to use a small pruner for very thick or very hard wood, it’s usually easier to use a bigger pruner for heavier jobs and stick with bypass for everyday use.

Bypass pruners come with all kids of blade lengths and angles, with and without ergonomic handles, and in special versions for lefties. They also come in a wide price range, with the best-made costing two or three times as much as the cheapos. Fortunately, even the most expensive pruners cost less than dinner and a movie for two, so there is no reason to stint. Just remember the old saying: good tools make all tasks go lightly.

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Bypass pruners

In fact, it’s best to have at least two pruners, one saved for rough work (at ground level, for example, where you might hit gravel) and one used for delicate operations like removing spent lilac blossoms.

This will let you go a bit longer between sharpening sessions. But those sessions are as important as the pruners themselves because it is absolutely essential to make clean cuts when you are pruning shrubs. Wood that has been torn or crushed, as is guaranteed to happen if the pruners are not sharp, is (literally) an open invitation to disease.

Just as it’s better to plant a five-dollar tree in a ten-dollar hole than the other way around, it’s better to have a pair of sharp cheap pruners than to work with quality tools that have been allowed to get dull. If you don’t want to sharpen them yourself, be sure to have them sharpened regularly by a professional — your local nursery or garden center can usually recommend someone. Keep your tools clean and oiled between uses so they don’t rust, and they should serve you well for years.

Prune that Raspberry patch

How-to-grow-raspberries-young-fruitUnderstanding how raspberries produce is the key to getting the most from them. While their roots are perennial, their canes are biennial, dying after the second growing year. In order to prune successfully, you have to know which canes bear when, and that is a function of whether are summer bearers or fall bearers.

Summer-bearing raspberries act like true biennials; the first year is for producing leaves, and the second year is for flower and fruit production. After that, the dead canes just stand around interfering with berry picking. Every year, raspberries send up new canes, so the penalty for not pruning — rampant sprawl and painful harvests — mounts.

The elegant way to prune summer-bearing raspberries is to cut all canes at soil level in the summer, after they are finished fruiting, and then prune out all but the strongest four or five new canes in the spring, once they are 8 to 10 inches high.

Fall-bearing raspberries, also (somewhat misleadingly) called ever-bearing, produce fruit twice; at the tops of the canes in late summer or early fall of the first year, and again lower down on the canes during midsummer of the second (and final) year.

Prune fall-bearers in the spring. For maximum yields, completely remove the canes that produced fruit during the previous midsummer (look for old, cracking bark on the two-year old canes). Leave enough of the brand-new canes to produce a late, first-summer crop, while removing as many as necessary to control the size of the plant.

Alternatively, you can simply cut fall-bearing raspberries to the ground each spring. You’ll get only the late crop of berries, but you won’t have to decide which canes are two years old and which ones are only one; you simply whack them all back.

Lilac Woes

Did you plant a lilac bush and have lovely flowers the first year and nothing since then? Or maybe you’re not getting the flowers that you used to get from your established lilacs?

According to Jack Alexander, the chief plant propagator at the lilac-magnificent Arnold Arboretum at Harvard University, newly planted or transplanted lilacs tend to have transplant sulks. Most spring-flowering shrubs, lilacs included, form flower buds the previous year. That initial display you see when you buy new shrubs was set when the lilac was still comfortably at home in the nursery. When it was moved, the disturbance set it back. Give it a bit more time, and whatever you do, don’t move it again!

flower-356176_960_720Common lilacs (Syringa vulgaris) and the French hybrids based on them are especially sensitive in this regard. If you’re the type who likes to move the furniture around, try planting ‘Miss Kim’ (a cultivar of S. patula). She’s a bit less fussy about an occasional relocation.

‘Miss Kim’ is easy to find at nurseries, as are a good number of S. vulgarisĀ varieties and cultivars. But for the widest selection of colors, fragrance, and bloom times, mail order is the way to go.

Pruning

Lilacs have to grow for a few years before they start flowering. After that, they bloom in spring on year-old wood, the stems that grew from the older branches during the previous summer.

Pruning consists mainly of removing elderly trunks and clipping off seed heads within reach. But if you want to cut back young growth, the proper time is right after flowering. It should be done as soon as possible, and no later than three weeks after petal fall.

Still not getting Flowers?

If you are not pruning too late or cutting off all of the new growth, the problem may be too much fertilizer, which could push vegetative growth at the expense of flowers. Or, maybe the problem is a lack of light. Lilacs need plenty of sun to flower well, and shade is the most common culprit when mature bushes fail to bloom.

Remember, too, that if you go through a summer of little or no rain, the plant will be unable to set buds for next year so you can expect little or no flowering the year after a drought.