Time now to WHACK IT BACK. WHACK IT GOOD! Its good for the plant and good for what ails ya. Gives you something to do when that nasty ennui has engulfed your otherwise chipper gardening spirit. And I am all about feeling good.
Try to get out in the garden early in the morning or late in the evening in order to spare yourself a heatstroke. Drink plenty of fluids: in the day time may I recommend lemon or cucumber water; in the evening I suggest wine (for moi, this summer I am enjoying Lora Dona Viognier, crisp and fruity when chilled, $10.49 at the Boise Co-op, but I digress) or your adult beverage of choice. Arm yourself with a good pair of pruners and some lopping shears.
I just cut my callirhoe involucrata back by half. Ditto the Grosso lavender and the hardy geranium, Roxanne, Rozanne, whatever name she is going by this week. Deadhead everything in sight. Clean it up. This serves a couple of purposes:first, after the plant blooms, it directs its energy to setting seed. I want to stop that behavior and encourage the plant to redirect that energy to the roots to keep them strong. I want the foliage to stay alive AND thrive during the next two to three weeks of continued high 90′s days. I may give the chlorotic sweet gum and a couple of shrubs a remedial dose of Save a Tree, but no more food for the perennial border plants. By removing all the excess stems and dried up blossoms, you are also depriving the grasshoppers and earwigs a huge chunk of their hiding space. I even gave the delosperma/ice plant a crew cut.
I will cut back the asters by at least a third – this will delay the blooms until September, when I really want them. If they start now, and they are trying to, they will be totally spent by autumn. I’ve been known to cut back my Joe Pye weed, too. I cut off the new blossoms. Severe you say? Yes, but they are struggling to stay hydrated in this heat, and they will snap right back and bloom again in 3-4 weeks and will keep blooming until late September. Call me crazy, but I don’t like being outside when it is over 90 degrees, so if my garden gets a haircut and snaps back by Labor Day, when I fully intend to go outside again, I consider this a win-win situation. I’ve been doing this whacking treatment for several years and have been very happy with the results. A great reference book on this technique is the Well Tended Perennial Garden by Tracy di Sabato Aust. Note: sedum Matrona, Black Jack, Purple Emperor and the other tall ones do NOT like to be cut back. They do not snap back, they pout and look stunted the rest of the year. Ewwwwww.
Pat yourself on the back for all this hard work and grab a big fat book. Seek shade and respite and ripe tomatoes.