Why prune? Listen to Kirsten

I traveled to Arlington, VA last weekend for the winter pruning instruction given by Kirsten Conrad Buhls, Extension Agent, and her well-trained Tree Stewards. It was kinda cold for note-taking, but thankfully there were hand-outs.

The crowd - about twice this number - was cold but willing.

Pruning Tips

Tree steward demonstrates thinning of dogwood.

Teachers of pruning always tell us to have a reason to make any cut – like the ones listed above, although.

Kirsten talked a lot about rejuvenation pruning, which is sooo needed by sooo many plants, yet so seldom done.  She explained that new growth happens where we make the cut, which is why we should generally avoid making cuts at the outer edges of the plant.  Instead, we can reduce the size and generate new growth from the center of the plant by removing whole branches all the way to their origin.  For most plants it’s best (and always safest) to remove no more than one-third of the plant at a time.  So for large overgrown, underperforming shrubs, remove one-third of the stems each year over three years, for a totally  new plant that’s much more vigorous.

Another important pruning tip we learned is to cut just above a node or branch, about 1/4 to 1/2 inch away.  That way, unsightly, unproductive stumps aren’t left hanging, and cuts are made where they can generate the most new growth – at those nodes where the growth hormones are.

Kirsten also suggested that for plants that are sheared, to then go back with hand pruner to “punch holes” in the outer edge of the plant.  By removing small clumps where the shrub is thickest, air, light and water are allowed to reach the interior of the shrub, thus stimulating growth there.   Click here for more tips about using this technique on boxwoods, from the experts at the National Arboretum.

More good pruning tips from the experts: the Morton Arboretum,  Colorado State, and the University of Georgia.

Shrubs to Prune in Winter (November through February)

Abelia, Arborvitae, Beautyberry, Boxwood (through July is fine), Butterfly Bush, Chastetree, Cherrylaurel, Clethra (Summersweet), Cotoneaster (both evergreen and deciduous), Crape Myrtle, Redtwig Dogwood, Thorny Eleagnus, Euonymus (evergreen and deciduous), Gardenia, Hibiscus, summer-blooming Hydrangea, St. Johnswort, Juniper, Nandina, Osmanthus, Photinia, Mugo Pine, Privet (both evergreen and deciduous), Smoke Tree, summer blooming Spirea, Sumac, and Yew.

Posted by Susan Harris.

Blueberries just happen to be 50% off until October 12th, so if you don’t have one already, now’s a great time to remedy that.  Lots of other fruit trees are half off, too, by the way.

You can hardly do better than a blueberry for a multi-season, multi-use shrub! Flowers in spring start out with pinkish buds and open to white bells, and then provide you and the birds with crops of beautiful, tasty blue treats in summer. (Or pink! There’s a new pink-fruited blueberry out now, called Pink Lemonade.) Foliage is seldom bothered by insects or disease, and gives you great burgundy, red, orange and/or yellow fall color. Bare stems in winter can be blushed orange and yellow on young bark.

Give blueberries full sun if you want to maximize your harvest; in the wild you can find them in open woods where they receive partial shade, though they don’t fruit as heavily. Soil should be well-drained and fairly acidic, which you can achieve with adding sulfur to your soil and monitoring the pH with a simple test kit. Aim for around 5.0 or even slightly lower. Blueberries are better equipped to handle wet conditions if in strongly acidic conditions, as this suppresses disease. Holly-Tone makes a great all-purpose fertilizer, and no regular trimming is needed. Both Highbush and Lowbush species of blueberry are native to the mid-Atlantic. If you have deer, you might need to net the plants to prevent browsing, but that will save more berries from the birds for you to enjoy.

by Susan Harris
I noticed in the latest Behnke e-newsletter that one of my all-time favorite shrubs – the humble weigela -  is on special.  50% off!  So while I stay away from advertising-type articles here on the blog, I can’t help but show off some of my favorite Weigelas because full-grown and in a garden setting, they make quite an impact.

I regularly recommend this shrub to my garden-coaching clients, telling them that Weigelas grow fast, are quite drought-tolerant, are unbothered by pests of any type (in my 25 years of growing them) and boy, can they fill up a garden.  Oh, and they’re pretty, especially when blooming.  Love the naturalistic, fountainesque shape.

Chanticleer Garden has lots of Weigelas, shown here behind Amsonias.

Close-ups of Weigela blooms in shades of pink.

'White Knight' in my garden.

Breeders are providing us with lots of smaller choices these days – like this ‘White Knight’ variety that’s almost white.  It’s only about 4 feet tall by 8 feet wide.

How do I maintain my Weigelas? After they’re settled in, I never, ever give them supplemental watering, so that tells you how drought-tolerant they are.  No fertilizer, no pesticides.  Just a bit of pruning after they’re full-grown, and the kind of pruning given is important.   No shearing into artificial shapes!  Just a bit of renewal pruning – removing a third of the stems all the way to the ground, sometime in late spring or early summer.  This encourages new growth while preserving the Weigela’s lovely natural shape.

'Yoshino' Cryptomeria

by Susan Harris
With our June drought still going strong and no rain predicted, let’s cover the trickiest plant group of all to water correctly – evergreens that don’t warn us of their impending demise by drooping, as so many deciduous plants do.  Some are more drought-tolerant than others, of course – thankfully! – so we don’t worry too much about junipers or nandinas, to name just two.  But care instructions for the glorious Japanese cedar (Cryptomeria) usually say they like “even moisture” and that’s a warning sign that shouldn’t be ignored.  Same goes for ‘Otto Luyken’ cherry laurels, one of which I did lose during a drought because of my own neglect.

So I asked woodies buyer Miri Talabac how to tell if evergreens need watering, and here’s her advice:

“Well, evergreens that don’t wilt are in double trouble, in a way – they can just as easily be overwatered by over-compensators who know they don’t wilt when dry. The best way is what I tell everyone asking about when to water – check the soil with your finger (or for the squeamish, a sharpened wood pencil). Several inches down, in the root zone, if the soil is cooler and moist, sticks to your finger a bit and/or wets the pencil wood, then you’re probably fine. Drier, and the plant should be soaked thoroughly. Water deeply but infrequently, that’s the best method to keep plants healthy.”

'Otto Luyken' cherry laurels in front of my house.

by Susan Harris
According to woodies-geek and rose-buyer Miri Talabac, Behnkes has about 200+ varieties of roses in stock, some in each of these types: Climbers, David Austin (English-type), Floribunda, Grandiflora, Hybrid Tea, Landscape, Miniature and tree-form (but very few).