Extreme heat with no rain? Praise be the plants that survive without watering!
Like so many of your gardens, mine is undergoing the greatest test of all – prolonged extreme heat with no rain. And I’m betting you’re like me in not having an irrigation system to rely on. (Never wanted one, though. Still don’t.) I’m in a humid hardiness zone 7.
So you may want to join me as I whine about how much hand-watering I’m having to do, even in my small garden. Which makes me more grateful than ever for the plants that I can still ignore under these extreme conditions, especially the larger plants and the ones that cover a lot of ground. I know that as temperatures rise they may not always survive but so far, so good.
Plants I never water, yet they survive
Here in one of my adopted gardens, at the offices of my housing co-op, the goal has been a good-looking landscape with the least possible maintenance – planning for when I eventually stop caring for it. So far, these plants have survived several summers with no supplemental watering – now that they’re all established – with less and less weeding, and a bit of pruning.
Shrubs: spirea, ninebark, and threadleaf false cypress. UPDATE: Four days later, the ninebarks were looking crispy, so I did water them. and remove the crispier bits.
Perennials: nepeta, black eyed susans, buterfly weed, phlox. groundcover sedum and liriope.
The lawn is cared for by the landscape contractor. I’ve never seen it being watered or doused with anything, though I can’t swear that it’s never done.
In this view from the main entrance you get a glimpse of the weed-free expanse of liriope that needs no care – not even cutting back in late winter. Just some edging, which the landscape crew does well. There’s lots more liriope on each side of the building. I get why people don’t love liriope but in places like this it’s damn useful.
Here in my lawnless home garden, these are the plants I don’t water, even when it’s hot and dry.
Shrubs: fothergilla, acuba, old azaleas, nandina.
Perennials: little bluestem, crossvine, amsonia, succulents.
Perennial groundcovers/lawn replacements: packera aurea and ‘Ice Dance’ carex, if given some shade. Liriope and sedum anywhere.
Plants I’m afraid will die if I don’t water them
Man, I can’t imagine going away in the summer because there are so many plants that need my help! There are the obvious ones – annuals and anything newly planted or transplanted – but also a lot that are “established” that I’m still watering in the hot-dry period we’re in now. Saving them in worth it to me!
To water the plants shown here at the far end of the garden takes some doubling up of hoses, and it’s easy to forget to even check this area because I don’t see it from the house. (Seen here are fothergilla, acuba, purple smokebush, ninebark, with carex and liriope covering the slope down to the sidewalk.)
I’m MOST afraid of losing evergreen trees and shrubs because they don’t warn us before expiring, say by wilting visibly. I have lost Arborvitae from drought, which led to yanking out all the survivors in the hedge I already hated. (And hand-watering an entire hedge of conifers? That’s a time-consuming and boring job! No wonder I failed to do it enough.)
Shrubs/trees: Arborvitae, boxwood, Japanese maples, ninebark, redbud, purple smoke bush, and fothergilla. I regularly water my oakleaf hydrangeas, of course.
Perennials: autumn fern, Joe Pye weed, wood aster, native honeysuckle, clematis, hardy ageratum, hardy begonia. (I have hopes that some of these will need less coddling over time, though.)
Perennial groundcovers: carex (if in sun), groundcover comfrey.
Advice from the Woodies Specialist at Maryland Extension
I asked Maryland Extension question-answerer Miri Talabac for her advice on this critical topic and she responded immediately, like she always does. (Before she worked for Extension I knew Miri as the woodies buyer for the much-missed family nursery Behnkes.) Here’s her answer:
- Prioritize any new plantings (in the ground less than two years) of woodies and perennials.
- This may go without saying, but prioritize any moisture-loving species (including those prone to dropping flowers or fruits if dehydrated), so for example, I’d focus on Winterberry and Clethra over, say, Hypericum and Caryopteris.
- As you noted, monitor carefully the plants that don’t show obvious initial signs (like wilting) of dehydration, like conifers and broadleaf evergreens. [I followed up by asking *how to monitor* and her answer was “Feeling the soil, in the 4-6” depth range. That’s really the only way to tell for sure if the root zone is getting too dry. Yeah, it’s tedious, but it beats waiting for stuff to wilt (if it ever does). By the time something wilts, root stress is pretty significant, and fine root hairs might already be dying off. Plants might recover if watered right away, but I would not recommend putting a plant through that degree of stress regularly by using that as someone’s only indication that watering is needed, because it means watering was needed well before wilting began.]
- Monitor plants that extensively share a root zone with a mature tree, like any groundcovers and newly-planted or rehabbed turf. (Mature turf can probably handle it, though don’t let it get so egregiously dry that the grass crowns die.)
- Closely watch any container plantings, since usually containers and raised beds dry out faster than in-ground and at-grade plantings. Vegetables bearing fruit with a high water content, and whose water uptake can impact conditions like blossom end rot (tomatoes), should be checked daily if they are in pots. Due to their root structure, blueberries are not very tolerant of drying out too much, and their relatives azalea, rhododendron, mountain-laurel, and pieris also don’t want to get too dry, though ironically are also sensitive to overwatering as well, which is why it’s important to check soil rather than making assumptions.
- Speaking of — to avoid overwatering by either watering on a set schedule or assuming a plant needs water based on weather or surface soil conditions, feel the soil by hand. Some soils might dry faster or more slowly than we expect, and unseen obstacles below ground (stone, construction debris, veins/pockets of a different soil type, etc.) can either hamper drainage or increase it. Monitor by touch at least four inches down (containers can be checked a couple inches deep, more or less…depth will depend on container size), and closer to six inches down for established woody plants. If the soil at that depth feels somewhat dry to the touch, watering is probably needed unless the plant in question appreciates or tolerates getting pretty dry between waterings. If damp to the touch at that depth, watering is probably not needed unless the plant in question happens to like staying wet.”
Thanks, Miri!
What are YOU watering?
What plants in your garden are worrying you – for good reason or out of sheer worry? (Sure beats worrying about the election, though.) And do tell us where.