We’re just about a week away from the first day of summer, so this week I thought we’d take a look at the passing spring season as well as do another review of some of last winter’s ravages and a few odds and ends. This is the June ramble.
While I don’t have any statistical information, the spring of 2014 has been unlike the previous few in that it’s been slow to start, with a very gradual build-up in both the air and soil temperatures. This is a good thing. A very warm or very dry spring would have stressed our landscape plants even further than the winter had, with the possibility of extending winter losses. The gradual warming, on the other hand, has kept many insects in check or slow to emerge, and the rain we’ve gotten seems to be right on target, along with ample amounts of sun once we got into May. This all bodes for a great gardening season. Maybe.
I’ve never seen deer browse on azaleas and rhododendrons like we saw this past winter. Even in fenced properties, if the deer could go over or under the fences, they seem to have headed for the rhody family. I saw evergreen azaleas nearly stripped of leaves and buds and the denuding of the rhododendrons was limited only by the neck reach of the deer. I saw one garden that was encircled by rhododendron roseum where the shrubs were leafless from the ground to three, four and five feet above the ground.
We’ve had such little experience with this kind of extreme browsing where half the plant was de-leafed that it’s been hard to give advice to readers and gardeners on how to remediate the browse damage. If there was any root damage associated with the prolonged deep cold, adding any fertilizer, which might stimulate new growth, could burn any damaged roots. Pruning might work, but how far back do you prune on a mature rhody to get new growth on a plant that has plenty of top growth but little on the bottom? And what to do with the varieties that suffered twig dieback from the cold?
Well, I fell back on my tried and true resolution to situations like this. When in doubt, wait … and do nothing. And so far that has turned out to be the right move. The azaleas have pretty much re-leaved, and now that they seem to be on the road to recovery they’re getting a light organic feeding to accommodate the new flush of off-season growth.
The large rhodies have also been a pleasant surprise. Just about every plant that had severe deer browse has produced new foliage, and while the new leaves are small, the refoliation looks like it will be complete in the next few weeks. Here again I’m recommending a light application of an organic fertilizer to balance the plant’s needs, as the new foliage is being produced at a prolific rate when the shrubs are needing added nutrition.
Another thing I’ve noticed on some of the shorter rhodies that had shoot dieback is that new shoots are developing along the branches and from dormant buds closer to the ground. This is probably taking place as a result of the release of auxins or plant hormones that we usually see coming into play when we prune. The pruning, or in this case the dieback, results in the auxin release, and that stimulates dormant buds along the stems to come to life as new foliage and emergent branches.
In all these cases, be it rhodies, azaleas or damaged hydrangeas, the key objective should be to tread lightly. It’s a big mistake to try and jolt these plants back to life by shooting them up with fertilizers. For now, small amounts of organic fertilizers like fish emulsions, kelps and compost teas are probably the best and safest encouragement you can offer. If you suspect root damage then look into a biostimulant that contains no nutrients at all.
If your hydrangeas haven’t done it by now then they won’t. It’s time to prune them back to new foliage unless you’ve got varieties that bloom on new wood. If you’ve got no new buds, just write the season off but not the plants. I still have two buddleias that haven’t shown any signs of growth on old wood and no signs of shoots emerging from the ground. Not giving up on them just yet though. One big surprise is the kniphofia “Elvira” that I’m trialing from Blooms. It made it through the winter (root wise) and has sent up a mass of new foliage that’s making me think it will flower profusely in July. If this actually happens it will be one of the first Red Hot Pokers that I’ve seen survive for multiple years and a severe winter.
I’ve been very slow in getting down mulches in my perennial gardens this year and there’s been an interesting result. By June I’m usually going nuts trying to control the first wave of slugs and snails. This year by the first of June I had only one of each. I’m now beginning to suspect that early applications of mulches allows these slimies to evade predators like birds … no mulch, no place to hide. Stay tuned on this one.
And if you’re looking for the best slug control known to man, then you want to become very friendly with your local toads. The common toad, bufo americanus, is a voracious eater of slugs and garden insects, and once toads have set up shop in your garden they stick around nearly forever. You need to have a toad-friendly garden though, and that means places for them to hide (dark and damp like under rocks, inside rock walls, near ponds and pools), and they need places to lay eggs and for tadpoles to develop. I’ve also read that some gardeners use toad lights. These are low-wattage lights that are left on at night in the garden. The lights attract insects at night and the toads learn to hang out nearby. It’s the toad’s version of a drive-in window at McDonald’s. And if you find toads in someone else’s garden don’t try to transplant them. A university toad expert tells me they have a great homing sense and won’t stick around unless they volunteer for work at your place.
Once my tall garden phlox (phlox paniculata) began to send up new shoots in early April I was all over them with my 10x loop looking for two-spotted spider mites. These mites have caused heartbreaking damage in my garden each summer just as my phlox reach their peak. I followed the experts’ advice and removed all the foliage and stems at the end of last season, and I was shocked to find the mites active by late April. We’ve always been taught that these mites thrive at the end of the summer when it’s hot and dry. So what’s up with them showing up when it was cold and wet?
Well, I began to hit my entomologist with this problem and he responded with a surprise answer—that females can overwinter and lay eggs very early in the growing season. So out the window goes the age-old teaching that two-spotted spider mites show up only when it’s hot and dry … unless you have an indoor gardenia, on which they seem to be endemic.
So my search for a “cure” began in earnest. Seems that two-spotted spider mites are also a problem on marijuana plants, and with all that’s going on out in Colorado with the commercialization of legal pot, there’s a lot of research being done on two-spotted spider mite control. And they said pot had no socially redeeming value. Hah.
Interestingly, the marijuana growers are pretty careful with what they spray on their pot and suddenly I had a couple of options that there was no research on just a few years ago. Bottom line was that I had great success with product called Pure Green Spray, which is 98 percent mineral oil that’s been highly refined. I also found that the miticide Avid was extremely effective as well as fairly benign. The problem with Avid was that it’s sold commercially for upward of $100 for 8 ounces. I needed only a few drops. I found an ounce container for sale on Amazon. Not quite sure it’s legal to repackage and resell this stuff but … it’s available and a little bit goes a long way.
I’ll have a few insecticide/miticide/fungicide recommendations in a few weeks but I’m out of time, out of room and the garden calls. Keep growing.