Wisteria – Growing Tips & Maintenance

A pink Chinese wisteria covering a pergola in Bonny Doon

Wisteria season is winding down unless you have a repeat bloomer like a ? Cooke?s Purple? or ?Amethyst Falls?. I?ve heard it all: ?Why doesn?t my wisteria bloom?? or ?I planted a wisteria in the wrong place, how do I get rid of it?? or ?I love my wisteria but it?s taking over the porch ?? (insert garage, house, shed or other structure) Seems we either love ?em or hate ?em on our own property. Growing somewhere else they are always the stars of the spring garden. If any of this sounds familiar to you here are some tips on how to handle yours.

Wisteria are 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.

A pink wisteria growing under a fragrant purple variety covers a gazebo.

Wisteria are so vigorous they can be pruned at any time, keeping them in bounds and clearing 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.

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 if there is an over abundance of luxuriant growth. Over feeding also ends up giving them the means to become unmanageable monster. If you have trouble getting your vine to flower an application of a high phosphorus fertilizer may promote blooming.

A diligently pruned wisteria at Filoli Garden

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. If you find that the wisteria vine has invaded a nearby bed, cut roots with a shovel below the soil line to control any that have wandered.

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

A Cooke’s Purple wisteria growing on a pergola in Boulder Creek.

Chinese varieties such at ?Cooke?s Special? have clusters of fragrant blue-purple flowers 20 inches long. This variety can re-bloom which makes it a favorite. Chinese wisteria can take up to 20 years to mature enough to produce flowers, but once it has matured, the plant is very long lived and can live up to 100 years.

Japanese wisteria like ?Caroline? bloom early with mauve flowers. ?Royal Purple?. known also as ?Black Dragon? , has sweetly scented dark purple flowers. Japanese wisteria are most effective when grown on pergolas so their long flower cluster can hang freely.

American wisteria, native to more eastern areas of the U.S. is a smaller, less invasive species that grows ar about a third the rate of Asian wisteria. ?Amethyst Falls? blooms at an early age with lightly fragrant purple racemes. Use in containers for porch or patio, train up an arbor or trellis or as a small free-standing tree.

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.

All parts of the wisteria vine contain a toxin known as wisterin which can cause stomach upset. Growers should also be wary of pets and children eating the flowers or seed pods.

Plant Problems- What’s a Gardener to do?

Just one of many banana slugs in my garden

Everything was growing nicely in the garden until the banana slugs and squirrels started eating me out of house and home, fungal leaf spots and aphids appeared and the gophers and deer decided they really liked my plants. What?s a gardener to do?

Troubleshooting is a form of problem solving. And whether it?s your car, your smart phone, an irrigation system or yellowing leaves on a plant the goal is to find the solution and make everything work again. When you eliminate the potential causes of the problem hopefully the solution restores everything to its working order. Sometimes this is easier said than done as we all know.

A few weeks ago I received a text with pictures of some plants with leaf spots and was asked for a solution. Over the winter we received a lot of rain so I wasn?t surprised. But if this were mid-summer I?d suspect that the plant leaves were burned by the sun and not getting deep enough irrigation. At this time of year, however, black or brown spots on leaves are fungal or bacterial problems and should be treated with an organic fungicide like Serenade which is non-toxic to bees and beneficial insects, Neem, copper or sulfur spray to prevent and control spreading. Affected leaves should be discarded.

The subject of how much fertilizer and what kind came up in another troubleshooting email. The issue was whether to use an organic high phosphate fertilizer in order to encourage bud development on a notoriously short-season tree dahlia. A single spring application of rock phosphate should be sufficient. Sometimes adding too much phosphorus can actually hurt a plant, preventing the uptake of other nutrients necessary to prevent other deficiencies. A balanced fertilizer containing all three nutrients- nitrogen, phosphorus and potassium-was recommended for the remainder of the season.

Winter yellow leaves on Meyer Improved lemon

Then there are the problems in my own garden. Well, it seems I am always trying to solve something with plants, pests or critters but now it?s the lemon tree. The older leaves of this tree are yellow. The new growth looks fine so it isn?t an iron deficiency where young leaves display green veins along with a yellowish color.

It isn?t a nitrogen deficiency either where the mature leaves slowly bleach to a mottled irregular green and yellow pattern, become entirely yellow and then are shed while the discoloration spreads to the younger leaves. I fertilized in March with an all-purpose balanced fertilizer. Citrus are heavy feeders and require a steady source of nitrogen, the ideal citrus fertilizer having a ration of 3:1:1 (N:P:K)

After eliminating other mineral deficiencies or overwatering as the problem I decided that my lemon was simply dropping interior leaves which is normal after winter but I wanted to trouble shoot all potential causes to be sure citrus greening wasn?t the culprit. If it had been this deadly disease the leaves would have exhibited an asymmetrical pattern.

To quote Sherlock Holmes ?Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.? I?ll try to remember that when I?m troubleshooting my next problem in the garden. Oh and by the way my banana slug relocation program is going well.

DIY Landscape DEsign Ideas

On a lovely spring day recently I spent some time in Palo Alto enjoying local gardens. It?s amazing what can be accomplished on a small lot where every foot counts. If you are looking to add some pizzazz to your garden and not spend much money, one of the gardens I visited will be right up your alley. Here are some take-a ways for your own landscaping.

Using driftwood collected from remote Santa Cruz beaches the owner of one amazing garden created a gate, several fences, flower bed borders to keep the dog out, an arbor and even a gazebo. He found used bricks and stones to build paths and also a patio but it was all the driftwood creations that caught my eye.

Take a few moments to really look at your garden. Look at the view from inside the windows and from the driveway as you enter. Then imagine all it could be with some simple changes.

A hand made driftwood arbor

The elements of garden design, like arrangement of paths, planting beds and open spaces, shape your garden. Have you ever noticed how your eye is drawn along a path through the garden? The plantings along the sides serve to frame but it’s the style of the path itself that enhances your experience in the garden.

The materials you choose for a path determine how fast or slow your walk will be. A casual path of gravel or bark chips lends itself to slow meandering around bends in the path. Flagstone pavers set in sand with spaces left between for low growing ground covers are good choices for both major access walks and smaller paths. Be sure to space the stones no further than a comfortable stride apart.

A curved line or offset sections of paving slows movement inviting you to notice the surroundings. Curves should look as if they are supposed to be there. Place a large plant, rock or sculptural feature at a turning point so that you must walk around the object. Remember a lightly curved path makes a nice entrance walk or a stroll through the garden but stick with straight lines for a path to take out the trash or get fire wood.

Used brick tapered path in a small garden

If your garden is small, a tapering path edged with curving flower beds will seem to converge on the horizon, giving the illusion of depth and distance. Plantings of grasses in the beds will create a sense of movement.

A redwood slab bench invites one to pause to enjoy the meadow.

You can separate plants and people by designing seating along the walkways. A good spot to place seating is at a fork in the path or where two types of paving meet another. Any object you can comfortably sit on is a possibility. Besides wood or ornamental iron benches, rocks, tree stumps, seat walls and planters can also double as seating.

Limit the number of elements in the garden. Rather than trying to include everything in the garden try for a unified look with the fewest number of things. Make each one count.

A short driftwood fence to protect a planting bed

Creating interest outside a window depends not only on plant choices but also simple design solutions. Keep the garden simple and restful. Editing some of the plants will make the garden lower maintenance, too. Plants that have overgrown the space need constant pruning. Move them to a better spot.

Another tip that makes an area more restful visually is to limit your plant palette. Plants that you can see through make a space seem larger. Some plants like Japanese maple, nandina and dogwood are naturally airy while other plants like camellia can be pruned for openness. Low growing, mounding ground covers help unify the garden. Plant soothing greenery for year round appeal with seasonal color from perennials and shrubs.

The great thing about making a garden is that you don’t have to do it all at once. And gardens are easy to alter as your ideas change. A garden is never done.

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