Tag Archives: pruning tips

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?

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Lomandra 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.

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Japanese 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.

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The 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.

Fruit Tree Care – Fertilization & Summer Pruning

Whether you grow one fruit tree or a home orchard full of them there is always something to learn from an expert and Orin Martin of UCSC Farm and the Alan Chadwick Garden is just the guy to help. With nearly 40 years of hands-on experience at UCSC he says he’s come up with a successful method of caring for fruit trees including pruning and fertilizing . “I’ve made every mistake in the book”, he laughs.

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Orin Martin explaining summer pruning

The UCSC Farm and Alan Chadwick Garden on the campus are both internationally known for training, research and public education. Recently I had the opportunity to join Orin during the Summer Orchard Walk at The Farm as he discussed the care of fruit trees and summer pruning to improve tree shape and productivity. Between jokes he shared many tips including the importance of fertilization and preparing an orchard for fall and winter.

Deciduous fruit trees are genetically programmed to start root growth early as they originated in the cold winter climates of Northern Iran, Uzbekistan and other central Asian areas. Their growing season begins in January or February which is 3-5 weeks prior to any visible bud swell when soil temperatures are still in the low 40’s. With this in mind Orin recommends starting fertilization early. Organic fertilizers take longer to become available to the tree and you want to maximize the early growth spurt in spring.

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Sunflowers attract pollinators to garden

Orin has a recipe for fertilizing young fruit trees that is used throughout the Farm and Garden. It’s comprised of compost and an organic source of nitrogen such as blood meal, 8% Nitrogen Sustane or Dr. Earth granular. A young tree will need additional nutrients in May and possibly July if the tree is not putting out sufficient structural growth. Fast acting liquid fertilizer such as fish emulsion and liquid kelp can be substituted for the early summer feeding. The second wave of growth occurs in fall. Slow acting organic fertilizer is best at this time.

Next year’s fruit buds are formed in late spring to early summer at the same time current fruit is growing so nutrient needs are extremely important at this time. If a mature tree is growing well its yearly fertility needs may be met by growing a bell bean crop as green manure over the winter.

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Ginger Gold apples with resident cats

The two resident garden cats followed our group as Orin demonstrated summer pruning of Ginger Gold apples, Flavor King pluot and Seckel pears. Most are trained to a open center with some having a modified central leader. I asked what he would do if no central leader grew after heading back a young tree whip. “Then I’d train it with an open center. You’ve got to play the hand your dealt”, he laughed.

“Ladderless” harvesting and care is the goal to pruning in summer and winter. Summer pruning from early August to mid September stops growth and is done to limit height and length of branches to encourage more fruiting shoots. Winter pruning creates the tree’s structure. “When you don’t want a tree any taller, stop winter pruning”, Orin told us.

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UCSC Farm crops

Throughout the orchard walk Orin Martin shared interesting tidbits of information. Seems that pest problems such as European blister mite and pear slugs are being observed here at for the very first time.

The USCS Farm & Garden has free monthly guided tours as well as a calendar of educational talks and events. It is open daily for everyone to learn and enjoy. Kids tours are offered during the school year in the Life Lab Garden Classroom.

Do I Really Need to Dormant Spray and Prune my Fruit Trees?

Gummosis canker on dwarf nectarine- Photo courtesy of Sherry Austin
Gummosis canker on dwarf nectarine- Photo courtesy of Sherry Austin

A Facebook friend recently posted a picture of gummosis on her dwarf nectarine. While pruning her fruit trees she found the sticky stuff and shared her plight. While some folks post pictures of babies and political opinions on their Facebook page, my friends post pictures of plants and their fruit trees. Yes, if you haven’t already done so, this is the time to winter prune fruit trees and apply dormant spray to fend off diseases and insect pests. With rainfall expected throughout the spring this is not the year to omit this important task.

Why prune your fruit trees in winter? The reasons to prune fruit trees are to increase fruit production, develop strong 45-degree branch angles to support fruit load, remove limbs that grow down or straight up, maintain tree size and maintain fruit spurs. The dormant season is the best time to train a fruit tree during its first three years. Pruning trees during the dormant period tends to have an invigorating effect on the tree. Good for a young tree, not so good if you are trying to control size.

Gummosis on plum in summertime
Gummosis on plum in summertime.

Pruning of dead or diseased branches can be done anytime, however, the sooner the better. And don’t prune suckers in the winter. This insures they will grow back in the summer. Over zealous winter pruning can result in waterspouts so go easy at this time of year. Summer pruning, done in June or July, decreases size and vigor which helps to slow the growth of a tree.

Often I’m asked whether to paint a wound with sealing compound after pruning. This is no longer recommended as it encourages wood rot. A tree is best protected by proper pruning technique and timing. With this in mind, don’t prune during late spring or fall as a tree is most vulnerable during those times. When you cut away part of a plant, a would is left, susceptible to pests and diseases. To avoid trouble always prune so as to make small wounds, rather than large ones. Trimming a bud or twig produces a smaller wound than waiting until it is a large limb. Rubbing off a sucker bud leaves a smaller wound than if you want until it has a year’s growth or more.

My friends sticky amber gum oozing from her dwarf nectarine branch is the tree’s reaction to stress. Cankers or sunken lesions covered with gum may be caused by mechanical injuries, such as lawnmowers or pruning, insects, winter damage, sun scald, herbicide injury or various fungal or bacterial infections. Practice good sanitation by removing and destroying cankered limbs.

You can prevent or control many diseases and overwintering insects by applying a dormant spray this month. This can be the most effective spray of the season. Fungal diseases such as peach leaf curl, fire blight, scab and anthracnose as well as insects including aphids, San Jose scale, bud moth, leaf roller, coddling moth and whitefly larvae, mealybugs and mites can all be controlled.

There are several types of dormant sprays and all three types are considered organic. Lime-Sulfur or copper can be mixed with horticultural oil which smothers overwintering insects and eggs. This spray is good for all fruit trees except apricots which should be sprayed in the fall with copper and this month with horticultural oil.

Apply dormant spray when the temperature is above 40 degrees. Make sure you cover every nook and cranny of each branch and trunk until the tree is dripping and spray the surrounding soil. Spray only plants that have suffered from pests or disease. Sprays, even organic, can kill beneficial insects as well. Even though they’re organic, dormant sprays can be irritating to skin and eyes, Wear long sleeves and gloves and eye protection.

I hope I don’t find any pictures on Facebook of your plant pests or diseases but post away if you something wicked your way comes and I’ll try to help.

Pruning Roses- How, When & Why

 

Mixed rose bouquet
Mixed rose bouquet

In between storms I’m itching to get outside and do something in the garden. It’s too early to cut back the perennials as some frosty nights are sure to come our way between now and mid-March. But it’s just the right time to start pruning the roses. It’s best to prune your roses before they start leafing out or some of their energy will be wasted.

Last year, mine were looking just fine in January, thank you very much, so I thought I’d skip the pruning and removing last year’s leaves. Boy, what a mistake. Oh they looked great in January and February when there was no precipitation. Then some rain fell in March. I’m not kidding when I tell you that every single leaf got black spot and rust. My rose varieties are usually resistant to disease but they could not fight back against the fungal spores lurking in the soil just waiting to colonize those old leaves.

Yellow fragrant rose
Yellow fragrant rose

Roses give so much back I think they are worth the extra mulch and a little extra water to keep them producing those lovely blooms. There’s nothing quite as dramatic as a mixed bouquet of scented roses on the table.

I want my rose bushes to produce lots of roses on a compact shrub and not just a few exhibition size blooms so I prune my shrubs moderately. My goal is to keep the center of the plant open for good air circulation aiming for a vase-shaped bush with an open center. I’ll cut out canes that cross, saving the better of the two, prune spindly and diseased stems and dead wood. I’ll also prune canes that appear weak or broken. Healthy canes appear green or reddish while old and dying canes are brown. Then I’ll cut back the remaining stems by about third. When pruning cut canes at a 45-degree angle just above an outward facing leaf bud or a swelling on the cane. Slant the cut away from the bud to encourage growth outward. Clean pruners afterward to prevent the spread of disease and keep your pruners sharp to make clean cuts.

Same goes for climbing roses. Cut out extra stems if there are too many and also cut back long established canes to the place where they are slightly thicker than a pencil. Then cut each side stem down to several inches. This will cause the cane to flower along its complete length for a beautiful spring display.

Bouquet of mixed roses
Bouquet of mixed roses

Heirlooms roses such as David Austin, other old antique garden roses, and floribunda roses require less pruning because their open look is part of their charm. Keep this in mind and prune lightly. Old garden roses that bloom once in the spring should be pruned after flowering.

I got off easy this year as one of my roses was pruned and de-leafed by a deer who got inside the fence one night but the others are getting pruned the right way and at the right time. I know those old leaves will spread fungus spores and possibly infect the new growth so I’ll patiently pluck them off.  If you have a huge climber this might not be possible and spraying with fungicide may be your only option if you’ve had disease problems in the past. Rake up the debris beneath the plant and discard to eliminate overwintering fungus spores. It’s a good idea to spray the bare plant, coating the trunk, branches and twigs and the surrounding soil with a combination organic horticultural oil to smother overwintering insect eggs and a dormant spray like lime-sulfur or copper soap to kill fungus spores. If you usually only have problems with black spot you can use a mixture of 1 teaspoon baking soda with a few drops of light horticultural oil in 1 quart water and spray every 7 to 10 days during the spring.

Pruning intimidates some gardeners but when you understand the reasons for making the cuts pruning becomes less daunting. The reasons to prune are for health, appearance and to control size.

Prune your roses throughout the growing season, too. Deadheading or cutting off spent flowers encourages plants to re-bloom. Every time you cut a rose bloom to bring it indoors or deadhead a fading rose prune the stem down to shape the plant at the same time. Prune to a spot that has at least 5 leaflets. Roses grow from the point where they are cut so consider the overall shape of the plant as you snip.

Don’t worry whether you’re pruning job is perfect. Roses are super forgiving and you can always trim them up again later. Roses are like redwoods -you can’t kill one- they’re the energizer bunnies of the plant world.

Pruning, Thinning and other Early Summer Tasks

Last week the first real taste of summer weather arrived and it was a wake up call for me. Over the past couple of months I’ve planted several new plants that will be drought tolerant once established but for now their root system requires more frequent watering than my established plantings. I’ll have to wait for the cooler weather starting in late September to plant any major additions to my landscaping. But for now I love to be out in my garden and there are lots of other things I can do to enjoy my time outdoors.

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.

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Japanese maples

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.

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Bing cherries

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.

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.

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Red Delicious apple

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.

And I’ll be looking for any pest problems so I can do something about them before it gets 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 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.

Hydrangeas-Summer Drama for the Garden and How to Prune Them

OLYMPUS DIGITAL CAMERAThere are some plants that are so showy in the garden they are worth budgeting a little extra summer water. They really get your attention.That plant for me is the hydrangea. Want instant drama in the garden? Plant one of the many hydrangea varieties. All have flowers so large they can’t help but steal the show. Easy to grow, they are pest and disease free. Here are some of my favorites and how and when to prune them.

Back in 2001 a new variety of hydrangea macrophylla was introduced. Called Endless Summer it has the unique ability to re-bloom throughout the spring and summer on both current and older season wood resulting in a much longer blooming season. This was great news for me because as sure as the sun rises, a heat wave would descend upon my garden in May and many of my traditional mopheads and lacecaps would crisp up and the show would be over way too soon. With Endless Summer I get continuous flowering through the summer. How do I prune this variety to get the most blooms?

When you read care instructions about pruning any hydrangea and they refer to new and old wood it’s really just another name for a stem they are talking about. New stems growing this growing season will be green. Old stems that grew last year are brown.

Prune Endless Summer hydrangeas as needed to keep them symmetrical. Remove dead stems you are sure will not be leafing out this year. To revitalize a mature plant-about 5 years old- remove about a third of the oldest canes in the spring by cutting them as close as possible to the ground. If your plant looks fine, leave it alone. You can prune off spent flowers in August but I prefer to leave the flower heads on the plant for winter interest.

Classic bigleaf hydrangeas -hydrangea macrophylla- mostly bloom on last years stems or old wood. The proper time to prune them is right after blossoming in July or August. Again I like to leave the dried flower heads on for fall and winter color so I prune lightly in late summer and again now lightly to shape. I may be cutting off some potential flower buds by pruning now but those stems usually flower by early fall and I’m not wacking back the whole plant.

If your bigleaf hydrangea doesn’t bloom well any more it may be time for more drastic measures. Cut back non-blooming stems to about 6 inches high. This will stimulate the growth of news productive stems.

hydrangea_paniculata_LimelightAnother showy hydrangea with huge pyramidal flowers is called hydrangea paniculata or Pee Gee hydrangea. With chartreuse blooms, Limelight is one of my favorites. They tolerate drought better than other hydrangeas which is another plus. Because they bloom on new wood in midsummer into fall, prune them in winter or early spring. Cut away old flowers and prune to open the plant to sunlight.

Hydrangea arborescens like ‘Annabelle’ produce enormous white flowers and also bloom on new wood during the summer prune during the winter or spring. This is the variety you see grown as hedges. I think I need one of these in my garden.

Vying for attention in my garden is the oakleaf hydrangea or hydrangea hydrangea_quercifolia_bloomquercifolia. I love this plant because it is so versatile. I often include it in a landscape design because it is easy to grow in a variety of situations from deep shade to mostly sun and it tolerates some drought. The stunning summer display of elongated, creamy white flower clusters age to pink by autumn and then papery, rusty brown in winter. But it’s the fall display of handsome leaves that resemble oaks that will get your attention. Mine turns the color of bright burgundy but I’ve seen bronze and crimson color on others. Prune them in early summer right after flowering.

Even in our coldest winters, hydrangeas in our area are easy to grow and don’t suffer winter damage to the flower buds as those in snow country do. Lucky us. I’m looking forward to my hydrangea show which will last most of the year.