JULY 22, 2010
July is for pruning
July is a very good month to do ďlightĒ pruning in our gardens. This always comes as a surprise to gardeners. Many of us think of pruning as a once a year task but nothing could be farther from the truth. The fact is that by the time we get to July our trees and shrubs and even perennials have put on considerable growth and need some guidance and direction. If we donít do some corrective pruning then we usually end up with over crowded and disfigured plants.
Pruning is a general concept as far as I am concerned. Mowing my lawn is really nothing more than a pruning operation. I do it about 36 times a year and each time my lawn gets just a little bit thicker. Dead heading a rhodie or pinching a snap dragon or fuchsia is also a pruning procedure. In these cases we are usually using only our fingers and not any clippers but nonetheless we are still pruning. So pruning is really a term we use to describe the process of removing growth, sometimes with a chain saw and sometimes with our fingernails. When it comes to summer pruning, less us usually better.
Now is the time to trim up those hedges like laurels and boxwood, Japanese holly and emeralds. The pruning we do this month will stimulate just enough growth to cover up all the shear marks and leave the hedge going into winter looking perfect. If we wait until September to do it then we will be looking at chopped limbs and leaves all winter.
July is a good month to shear our groundcovers if they have gotten a bit rangy. Yes, groundcovers like ivy, cotoneaster, Hypericum, Kinnikinnick and Vinca will all look much more attractive if they are shorn once a year. You can do this at the start of the season or now using a lawn mower set on the highest setting, a string trimmer or a hedge trimmer. (Mowing ivy will keep it from flowering and setting seed and spreading into native areas.) BTW, after you mow your groundcover it is a good idea to spread some lawn food to stimulate some fresh growth and to apply a weed preventer like Preen to keep any weeds from germinating this fall.
Fruit and flowering trees can be shaped now and all those water sprouts (sometimes called suckers) that form on flowering plums should be removed and not nearly as many will come back next spring. New growth on fruit trees and vines like wisteria can be cut half way back now for a more bushy and compact plant next season.
Fall blooming perennials like asters and mums should have been cut back once or twice by now to keep them shorter and more compact. Usually I recommend doing this no later than July 4th or you can damage the fall blooms. With it being so cold for so long you might still be able to get away with it but if you see anything that looks like a flower bud then donít do it.
Speaking of perennials, mine tend to grow together so much by now that I will go in and thin some of them so they arenít laying over each other. This kind of thinning can really be done any time and probably should be done more than once during the season. My Joe Pye weed starts flopping over onto all the adjacent plants so I just removed a dozen or so stems. Itís all about keeping my floral compositions in balance. As perennials go out of bloom the old flower stalks should be completely removed immediately so they donít go to seed. Some perennials like Delphiniums and Yarrow will actually bloom a second time if you do this. If you like to feed the birds then go ahead and leave some seed heads on to mature but be careful which perennials you do this with. Fennel for instance will reseed itself all over the garden if allowed it to go to seed.
Roses need pruning continuously throughout the summer. As the flowers fade look down the stem until you see a leaf with 5 leaflets facing outward and cut just above where the leaf is attached. The new shoot that emerges from that spot will produce a new crop of flowers in about 4 weeks. Keep pruning and feeding and you will enjoy roses all summer long.
Plants that weep like laceleaf maples, weeping willows and weeping cherries and weeping pussy willows and all the various weeping conifers will continue to grow downward until they touch the ground at which point they will spread like a groundcover. You can cut these back anytime you feel like it. Shorten them up at random lengths so they look more natural.
Another good reason for summer pruning is that those pruning cuts will heal much faster on a plant that is actively growing then one that is dormant. Faster healing wounds mean less chance of disease and stronger wood.
So while February and March are good times to do serious pruning, July is perfect for snipping and clipping. Sharpen those pruners and shears and get to it. Your plants will be glad you did.
Steve Smith is owner of Sunnyside Nursery in Marysville and can be reached at the nursery at 425-334-2002 or email at email@example.com