Category Archives: pruning tips

How to Live in Peace with a Wisteria

A wisteria is one of those plants that you either love or dread. One of nature’s most resilient survivors they are able to withstand and recover quickly from difficult conditions. To some they are a little too tough for their own good with a growth rate rivaling bamboo during the summer. If you dream of a wisteria-covered pergola shading your patio here are some maintenance tips that are sure to keep both gardener and vine happy.

Wisteria at Filoli Gardens in Woodside

Wisteria are so vigorous they can be pruned at any time, keeping them in bounds and to clear out unwanted or dead growth. Prune out any stems you see extending into eaves, windows or shingles. If yours has gotten away from you, you can even prune it down to the ground and start over with training although you’ll have to wait a few years for your vine to bloom again.

To their control size major pruning is done during the dormant season. Start by trimming the long tendrils that grew over the summer back to about 6 inches from the main trunk. Cutting the tendrils back in this way will initiate flower bud development, neaten the plant up, and show off the attractive trusty, gnarly character of the vines.

Pruning during the dormant season will also give you a fighting chance of keep your wisteria from getting into mischief. As you know if you have a wisteria, those long tendrils are capable of growing another 25 feet during the summer.

Wisteria shading a patio

Whatever time you do renovation pruning remember the response of the wisteria to aggressive pruning is to literally explode with new runners. They put energy into new vegetative growth at the expense of flowering. Make sure you keep up on ongoing maintenance pruning by removing all unwanted runners right to their point of origin. Then prune back the others to 3 buds or sets of leaves. Repeated pruning of these runners is what will eventually give you spurs of wood, short laterals that in turn will provide you with flower clusters. You need to prune these runners all season long which ends up being every 3-4 weeks.

Do not fertilize your wisteria. They do not flower well is there is an over abundance or luxuriant growth. Over feeding also ends up giving them the means to become un unmanageable monster. If you find the wisteria vine has invaded a nearby bed, cut roots with a shovel below the soil line to control any that have wandered.

Maintaining a wisteria requires some diligence but the reward is worth the effort. Remember this especially during winter pruning season to make summer maintenance easier.

Cooke’s Purple wisteria

Which variety of wisteria should you get to cover your arbor, pergola, tree or other structure?

Chinese varieties such at ‘Cooke’s Special’ has clusters of fragrant blue-purple flowers 20 inches long. This variety can re-bloom which makes it a favorite.

Japanese wisteria ‘Caroline’ blooms early with mauve flowers. ‘Royal Purple’ (also known as ‘Black Dragon’) has sweetly scented dark purple flowers. Japanese wisteria are most effective when grown on pergolas so the long flower cluster can hang freely.

Silky varieties produce a profusion of short, 6 inch, fat clusters of strongly scented flowers that open all at once. They have velvety seed pods and bloom best in full sun.

 

Why Prune in the Summertime?

Pruning is a good way to spend a couple of hours in your garden. I’m not talking about trimming plants into little balls but the kind of pruning that makes for a healthier and happier plant.

Sango kaku Japanese maple- summertime

If you grow Japanese maples now is the time to remove dead branches and train your tree to look like one of those specimens you see in the magazines. Thinning cuts build your ideal tree limb structure. If yours is a young tree, though, don’t be tempted to head back long branches too soon. As these mature they give your tree that desirable horizontal branching.

This principle is important to keep in mind when you train any young ornamental tree. Lateral buds grow along the sides of a shoot and give rise to sideways growth that makes a plant bushy.

Summer pruning of fruit trees controls size by removing energy-wasting water sprouts. Summer is also a good time to remove leafy upper branches that excessively shade fruit on the lower branches. Winter pruning is meant to stimulate the tree. Summer pruning uses thinning cuts-where the branch is cut off at its point of attachment instead of part way along the branch- and these cuts do not encourage new growth but control the size of your tree making fruit harvest easier.

Summer pruning also can control pests like coddling moths, mites or aphids. Just be sure to dispose of these trimmings and don’t compost them.

Espalier apple tree

If you have apricots and cherries, summer pruning only is now advised as they are susceptible to a branch killing disease if pruned during rainy weather. Prune stone fruits like peaches and nectarines after harvest by 50%. They grow quite rapidly. Apricots and plums need to have only 20% of their new growth pruned away.

Be sure to thin the fruit on your trees. That’s another good reason to keep them smaller so you can more easily reach the branches. The best time to do this is when the fruit is still small. Thinning fruit discourages early fruit drop and improves the quality of the remaining fruit. It helps to avoid limb damage from a heavy fruit load. Also it stimulates next year’s crop and helps to avoid biennial bearing. Left to their own devices, a fruit tree may bear heavily one year and then light or not at all the next year. Some types of fruit trees like peaches and Golden Delicious apples are likely to bear biennially if the current year’s fruit crop isn’t thinned.

While I have the pruners out I’ll be shearing back early flowering perennials to encourage another round of blooms. And I’ll add some more mulch to areas that are a little thin. I’ll be checking the ties on my trees to make sure they aren’t too tight and remove the stake if the trunk is strong enough to support the tree on its own.

Also I’ll be looking for any pest problems so I can do something about them before they get out of hand. I’m OK with a few holes here and there but a heavy infestation should be trimmed off or sprayed with an organic insecticide. I also inspect the tips of my fuchsias regularly for fuchsia mites and clip off any distorted growth. I hate to spray even organics on them due to the hummingbird activity.

Most importantly, enjoy your time outdoors. If a task is too big to do at one time, break it down into smaller sessions. As they say, take time to smell the roses.

 

June in the Garden-What to Do?

I didn’t get everything done in May that I had on my to-do list. Who ever does? Anyone who tends a garden knows how fast plants grow with the longer, warmer days and nights. So this month I continue to work on my own garden tasks as well as help others renovate their gardens to look great, support native pollinators, wildlife and habitat.

If you battle dandelions and don’t want to use chemical weed killers around pets and children, get out the white vinegar from the cupboard. On a hot sunny day spray straight white vinegar directly on the weed. This method will kill whatever it touches so direct the spray carefully. If the dandelion is in the lawn, wait a week, pour some water on the dead spot to dilute any lasting effects of the vinegar. Then poke a bunch a holes and drop in some grass seed. Sprinkle a bit of fertilizer where the seed is planted and keep the area moist. In three weeks you won’t remember where the dead spot was and the dandelion will be long gone.

Many plants, both vegetable and ornamental, are bothered by aphids and other sucking insects as well as foliage and flower eating bugs. From cucumber beetles, flea beetles, stink bugs, weevils, curculios to borers, the list of trouble makers is endless. To help deter them mix up some pepper spray in your kitchen.
1 tablespoon hot pepper sauce or 1 teaspoon cayenne pepper
6 cloves garlic, crushed
1 quart warm tap water
Let stand I hour, strain and spray plants either in the morning or evening.

Pink rhododendron.

When the last flowers of your rhododendron, azalea, camellia, weigela and spirea have finished it’s time to prune them. If you prune too many months after flowering your risk removing the flower buds forming for next year. Basically it’s best to prune lightly each year to shape plants that have become too leggy. The rules apply to most plants. Prune to the next whorl or set of leaves. To increase rhododendron bloom next year, break off any faded flower trusses just above the growth buds being careful not to damage the new buds.

Swallowtail feeding on lemon

Apply the second fertilizer application for the year to your citrus and fruit trees. The final one for the season should be immediately after harvest. Apply the fertilizer to the soil around the drip line of the tree where feeder roots are located and scratch into the surface. Water in well. As with all fertilizers, make sure the trees are moist before you fertilize. Young trees in their first, second or third growing season should receive half the rate of established trees.

Another garden to-do this month includes summer pruning of wisteria. To increase flowering next spring and keep these vines under control cut new growth back to within 6″ of the main branch. If you want to extend the height or length of the vine, select some of the new streamer-like stems and tie them to a support in the direction you wish to train the plant.

Erysimum ‘Apricot Twist’

Another maintenance tip is to shear spring blooming perennials to keep them full and compact. Candytuft, phlox subulata, aubrieta and other low growing perennials benefit if you cut off spent bloom and an inch or two of growth. Other perennials and shrubs that benefit from the same treatment to keep them compact are erysimum, lavender and Pink breath of heaven.

November Tasks in the Santa Cruz Mountain Garden

Outside my window, the Forest Pansy redbud has started to display its spectacular orange fall color. There’s a suet feeder hanging from the branches so I get to enjoy the antics of the Pygmy Nuthatches, Purple Finches and the Chestnut-backed Chickadees all day long as I watch the changing colors of the foliage. Other than watch the birds and the changing foliage colors what should I be doing out there in the garden?

hedge_parsley_weedHedge parsley aka Torilis arvensis

Light weeding is easy now that the soil is soft and moist. The dreaded hedge parsley has germinated early with our October rains. With it’s spiny-ball seeds that stick to your dog’s fur and your socks it is not welcome on my property.  It’s invasive and a native of Europe. They’ll be easy to pull now.

Maybe I will plant a few more bulbs. The ground is cooling and there’s still plenty of time for them to receive adequate winter chilling. Come spring I’ll be happy I did.

california_poppiesCalifornia poppies

I just planted wildflower seeds on my hillside. I hoping for more California poppies. I see some of last year’s wildflowers have reseeded. Nature knows when the time is right. I spread the new seeds in swaths and worked them very lightly into the soil, first hoeing off some early weeds that would compete with them.

What not to do in the garden now? I don’t need to prune trees and shrubs at this time of year. Other than clipping a few well placed branches to use for holiday decorations, I’m off the hook for this task. Deciduous trees are still in the process of losing their leaves and are not fully dormant. Evergreen shrubs and conifers can be trimmed lightly but most shaping is done when they start growing in late winter or very early spring. Fall is not a good time to prune. Wounds heal slowly, leaving them more susceptible to disease. As a general rule, don’t prune when leaves are falling or forming. To avoid sap flow on birches and maples prune after leaves mature next year.

hakonechloa_winterJapanese Forest grass in winter

The growing season is pretty much over for me except to enjoy what’s left of fall color and the ornamental grasses waving their seed heads in the wind. A lot of perennials are dying back but I’m not in a hurry to neaten things up. The seed heads left in the garden supply food for birds and other creatures while the foliage provides shelter for the plant in the cold and frost. Remove anything that has turned slimy or just plain unattractive but leave berries and seed heads for food and winter interest.

At this time of year my garden is visited also by Lesser goldfinches and warblers who will spend the winter and I’m doing them a big favor by not cutting back brown foliage containing nutrient-rich seed heads. Some of the reliable seed producers that I won’t have to clean up this weekend include artemisia, aster, coreopsis, penstemon, sedum, lupine, salvia, black-eye Susan, coneflower, phlomis, monarda, agapanthus and grasses.

Used to be the first frost in our area came about the first or second week of November but not anymore. Be prepared whenever it comes by moving frost tender plants under overhangs if possible or having frost blankets ready to cover frost tender plants.

Pruning Ornamental Grasses

Who doesn’t love a garden filled with the movement and beauty of ornamental grasses especially during the fall? But how do you take care of them after the show is over for the season?

lomandraLomandra and NZ flax in mixed planting

When I recently received an email asking what to do with an ornamental grass that had already turned that soft tawny color I figured it was time to brush up on how to care for them. To prune or not to prune? That is the question.

Grasses are distinguished from other plant families by their growth habit. They grow upward from the base of a leaf or shoot and can regrow from the crown when cut back. True grasses generally have extensive root systems which help control erosion. There are other grass-like plants like chondropetalum, New Zealand flax, kangaroo paw and lomandra that resemble grasses in their growth habits and are often some of the best companions for interplanting with grasses.

Most grasses require little care, minimal fertilizer and only occasional grooming. Some flourish with just enough water to meet their needs while others need regular irrigation. Diseases and insect pests are rare and they are not attractive to deer. They have succeeded because of their adaptability and have evolved to suit almost every environment and climate on earth.

japanese_blood_grassJapanese Blood grass – small and goes dormant

Basically, grasses and grass-like plants fall into 4 different pruning types: Large or small types that go dormant and large or small types that stay evergreen.

Large grasses that go dormant such as miscanthus and calamagrostis are pruned yearly in late fall to late winter. It’s best to hold off on pruning as long as possible to preserve the winter interest and to provide food for birds. When they turn brown and start shedding it’s time to prune. Gather the blades together with a bungee cord or rope and cut down to 10 inches.

Small grasses that go dormant such as Japanese blood grass or fountain grass should be pruned yearly at the same time. Don’t cut them too close to the crown or you risk losing a few clumps. Cut those under 3 feet tall down to 3 inches and those that grow taller down to 6 inches.

guardsman_flaxThe Guardsman- NZ flax large & stays evergreen

Large, evergreen grass-like flax and cordyline can be pruned anytime to cleanup and resize but rejuvenation should be done mid-spring. When pruning to freshen up the foliage, select the most damaged leaves and cut them out at the base. If your plant is overgrown or suffered winter damage, prune severely in mid-spring cutting off all the foliage at the base. Tall cordyline varieties can be cut off a few feet from the ground and they will re-sprout below the cut or from the base.

Lastly, small evergreen grasses like carex, acorus, blue oat grass and blue fescue grass can be cleaned up in spring by putting on rubber gloves and combing through the grass. If this kind of cleanup isn’t enough you can reduce the height by two-thirds and in a couple of months they will look good again.

Confessions of The Mountain Gardener

Everything in my garden does not always turn out the way I imagined. I make lots of mistakes. From putting in all the drip emitters backwards- yes, I actually did that- to my ongoing banana slug relocation program I should be able to face challenges in the garden and come out triumphant. But alas that is not always the case.

gauraGaura linheimeri ‘Belleza Dark Pink’

If you’re like me there are always plants that end up in the wrong place. My Gaura languish and reach for more light. My mildew resistant crape myrtle never recovered from last May’s foggy weather and has nary a blossom. Other plants shrivel up in too much sun. The possibilities are endless. Every garden is different. A plant that should be able to look great growing in full sun might get too much of a good thing in your garden planted up against a wall or near a flagstone patio. Conversely, some plants that should bloom just fine in partial shade never really do in parts of my garden or grow sideways reaching for more sun, finally flopping over in a valiant effort to get enough light.

I study my sun and shade patterns throughout the year. Really I do. I plant similar plants together in hydrozones to maximize irrigation efficiency. But still as the season winds down it’s obvious that I have made bad decisions along the way. Throw in the rogue gopher, the dog digging for said gopher and the occasional deer and mole and I seem to remember more failures and near-misses that successes.

gaura_reaching_for_lightGaura reaching for more light

I hope to learn from my mistakes and it’s never too early to start. Now’s the time to move those plants that will never do well where they are now. It’s time to plant new ones including native plants or transplant those in containers into your garden. October through February offers the best time to do this. In the fall the soil is still warm which encourages rooting and rain will be coming soon. Late winter offers natural rainfall to help plants establish before the next warm season arrives. Rearranging the garden makes for satisfactory fall work. After all you already own some of the plants, no need to buy everything new.

Transplanting and installing succeeds best if you take care of the roots as well as the top of the plant. Good growth comes from root health. Here are some tips for happy roots.

Prepare the new location first before transplanting any plant. Dig a hole twice as wide as the rootball but just the same depth. If the hole is dry fill it with water and let drain. Amend the native soil. Don’t be shy about loosening roots. Cut roots will form new, dense, healthy roots. Don’t add soil over the rootball. Keep the rootball a little higher than grade to allow for a layer of mulch and for any settling. Plants need oxygen at the soil level. Firm the soil after planting and water thoroughly.

Lessons I have learned that are easier to follow include when to expect our first frost. I’ve kept a weather journal for many years. Weather patterns change from year to year and we get updates from the media if frost is expected. You should prepare now as the first frost can come in November. Occasionally we have had a late October frost but mostly the first frost arrives about the second week of November with late November being the most common. Be prepared by bringing in your houseplants and moving frost tender plants like those fancy succulents under an overhang or porch.

I’m not sure when I’m going to be planting my wildflower seeds. Normally, I’d do it now but with the potential heavy rains we are hoping to get. I think I’ll hedge my bets, planting some now and another batch in February. By waiting until late winter I’ll be able to hoe off any tall weeds that have germinated that would outcompete the wildflowers.

One last thing and you’ll be happy to hear this. Fall is not a good time to prune. Wounds heal slowly, leaving them more susceptible to disease. As a general rule, don’t prune when leaves are falling or forming. To avoid sap flow on birches and maples prune after leaves mature next year.