DROUGHT….If you have spent any time in your garden this spring, I don’t need to tell you that we’re in the middle of a terrible drought, and it’s the beginning of June!!! The rains we normally see in May were MIA. The soil is extremely dry and cracked. I finally broke down and started watering, but these conditions don’t bode well for our plants, especially those newly planted. My advice remains the same as always – just do whatever you can. The best would be a good soaking 3x/week between the hours of 5p – 10a. You want to give the water plenty of time to soak deep into the soil before the heat of the sun causes it to evaporate. If you can only water 1x/wk, it’s certainly better than nothing. Try to avoid a short spritz since you are trying to teach your plants how to be resilient even when watering is skipped for several days.
HEUCHERA – TRIALS AND TRIBULATIONS…. Heuchera / Coral Bells have exploded on the market. A huge number of cultivars are available with foliage that adds color and texture to your garden. Some growers boast over 30 different cultivars to attract your creative eye, especially in the spring when the foliage is at its peak. I’m sure you’ve been tempted by some of these, and there’s a good chance you’ve been disappointed. My apologies to the growers, but many of these beauties just don’t seem to last very long. I tend to torture plants in my garden with part shade conditions and very little water, so if they last in my garden, then they’re likely to be a good bet in yours (as long as you can keep the deer away). Though rabbit resistant, the deer do enjoy nibbling.
Heuchera villosa is native to the mid-Atlantc area. Heuchera villosa ‘Autumn Bride’ with it’s medium green foliage and white flowers in the fall may be a little boring, but it’s a strong performer. It lasts for years and fills in nicely. There have since been quite a few cultivars introduced that are considered a Heuchera villosa strain. Theoretically, these should perform better for us, so try some of these first. Years ago, I selected Heuchera v. ‘Georgia Peach’ for one of my display gardens. I loved them, but they only lasted about 5 years, gradually dwindling to nothing. I tried Berry Smoothie a few years ago. Some went in the ground, and a few in containers. The plants in the containers are about double the size of the plants in the ground. They stay outside all winter, no insulation and no water. This is their 3rd season in the container, and they still look great. I have no clue why. There are a few that have done well in my garden…Heuchera ‘Green Spice’, Heuchera ‘Citronelle’, Heuchera ‘Palace Purple’. Heuchera ‘Rio’ has been a stellar performer so far, but this is only year 2. Top performers in the Mt. Cuba Center Trials include…’Citronelle’, ‘Frosted Violet’, ‘Plum Pudding’, ‘Southern Comfort’, ‘Spellbound’, ‘Autumn Bride’, ‘Bronze Wave’, ‘Caramel’, ‘Apple Crisp’. Test some in your garden, and find out what works for you.
CAREX PENSYLVANICA….About 5 years ago, I decided to replace some of my turf grass areas with Carex pensylvanica. The turf grass was struggling, and the lawn mowers were creating ruts that contributed to erosion. I thought that if I could eliminate the lawn mowers, then maybe I’d be able to prevent erosion as well. I planted plugs of Carex pensylvanica about 1” in diameter, and placed them about 1 ft On Center. These were large areas, and I wanted to stretch my dollar. The plants spread via below grade runners. In the low-lying areas, most of the Carex died due to root rot. There is now a variety that can handle the wet soil, Carex amphibiola, but I decided to simply go with an aggressive slug of a plant, Senecio aurea, instead. Senecio aurea can tolerate wet conditions, and is frequently utilized in Rain Gardens. The rest I kept with Carex pensylvanica. As the plants grew, of course the weeds found purchase as well. For 3 years, I tried to keep the weeds under control, down on my hands and knees, carefully wielding my soil knife. Unfortunately, I would frequently unearth a new baby plant with the weed, diminishing the speed with which it would spread. Last year, just as I was ready to throw in the towel, I decided to give it one more chance. This time, instead of weeding, I would cut the weeds down to the 4-6” height of the Carex pensylvanica. To my surprise, this method worked. After almost 4 years of struggling, it’s really starting to look soft and green, and gradually, the Carex is crowding out the weeds.
WEEDING…I do not recommend attempting to weed everything at one time unless you are working with a good crew. Instead, just tackle a small area at a time. If you are walking around and can pull only a handful of weeds, do so, and lay them just outside the bed for disposal at a later date. I usually only do the disposal 1x per week. If you have 1 hour to weed, pick the most offensive area, set your timer, and simply stop when the time is up. At least you will have started the process. I usually have trouble stopping, and my back is always angry with me later.
POISON IVY…Watch out for the Poison Ivy while gardening. Please check out my Poison Ivy Primer for some helpful suggestions.
HELLEBORUS….The flower stalks on Helleborus should be cut back close to the ground around the beginning of June. If you still have flowers on your plants, do cut them back if you have the time. A lot of energy will go to the development of seed rather than the growth of the plant. If the seeds are allowed to disperse, you may wind up with hundreds of baby plants. These babies are easy to transplant if desired.
PERENNIALS THAT FLOP….Some perennials become so tall that they become top heavy, and have a tendency to flop, especially after a good rain. Many of us resort to bamboo stakes and ties to keep them upright, but for some plants, there is an easier solution. In June, cut the plant height in half before it starts to flower. This encourages additional branching and a shorter ultimate height which in turn prevents the ‘flop.’ The plant may bloom a little later than normal, but it will still bloom and be lovely. Some of the ideal plants for cutting back include: Aconitum, Aster, Amsonia, Baptisia australis, Boltonia, Coreopsis tripteris, Eupatorium (Joe Pye Weed), Phlox maculata or Phlox paniculata, Platycodon grandiflorus, Sedum ‘Autumn Joy’, and Helianthus salicifolius. Pinching is another good option, especially for Sedum. Snap off the top 1/3 to 1/2 of each stem by hand (they do snap off if you do this with a quick motion). It actually does not take that long to do, and the outcome is much better than if you simply shear the plant. If your flopping plant does not appear on this list, contact me. I’ll be happy to look up the specifics of your plant.
PERENNIALS THAT REBLOOM…AFTER DEAD HEADING….You will be able to coax an additional bloom from many of your perennials if you dead head them immediately after blooming. This works extremely well with Echinacea / Coneflower, Leucanthemum / Shasta Daisy, Salvia, and Veronica.
PRUNE SPRING FLOWERING SHRUBS…. Now is the perfect time to prune spring flowering shrubs such as Azalea, Fothergilla, Oakleaf Hydrangea, Pieris, Rhododendron, Spiraea and Viburnum. After the flowers have dropped off, you can safely prune, and the plant will have plenty of time for the buds to set for next year.
PERENNIALS AND HERBACEOUS SHRUBS THAT BENEFIT FROM SHEARING…Some Perennials and Herbaceous Shrubs can be pruned after flowering, and will have the appearance of a shrub all season. Most notably are Amsonia hubrichtii / Threadleaf Bluestar, Baptisia australis / False Indigo, and Paeonia lactifolia (the Peonies that start fresh from the ground every year). For the Amsonia and Baptisia, I simply shear these below the spent flowers, creating a nice soft mound. The Peonies should be selectively pruned back to foliage you like. With this plant, be on the lookout for Powdery Mildew. When that appears, cut the plant back to the undamaged foliage. At the end of the summer when the Powdery Mildew appears on my plants, I simply cut the whole plant down to the ground.
RENEW UNSIGHTLY FOLIAGE…Foliage, especially perennial foliage can discolor during the growing season either from too much sun (Sun Scorch) or too much humidity (Powdery Mildew). There are other afflictions as well, but the key is whether the appearance of the foliage bothers you. If so, cut down the plant to the height of fresh new foliage or 2-3 inches in height if there is none. Usually, the plant will generate new, healthy, disease free foliage that season. In the rare case that foliage does not reappear, don’t panic. There is a very good chance that the plant will still appear again next year.
