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.
Terrific list and terrific advice from Miri too. “Prioritize” is my first priority in drought management, because I’m on watering cans and collected water. Vegetables are first on that list, but in terms of the ornamentals – probably the dahlias (and the amount I grow has SIGNIFICANTLY decreased because of this reason. I listed a bunch of plants doing well with this weather in my latest letter to Scott. We agree on a bunch of them – I just couldn’t list them all. Ninebark surprisingly solid! – MW
Yeah, Miri! …and thankyou Susan for bringing the subject up! I garden in high shade so there is no space without tree root innervation. To add to that, I have just expanded several new areas, so I have new plants and I am heavy on azaleas with their fine roots. Right now spring blooming shrubs are forming flower buds. If I want a good display next spring, I need to monitor my beds closely.
My beloved Edgeworthia, which I stupidly planted too close to a River Birch. That was years ago, but its the only of my established plants I need to water. (Birches truly are water hogs.)
My standard is ‘benign neglect.’ Plants that need pampering just don’t make it on my property. I didn’t consciously plan it that way, but that’s the way it worked out over the years and I’m much happier for it. I don’t “need” to spend a certain amount of time in my gardens every week, or even month, to have gardens I enjoy, and plants that appreciate not being bothered.
Zone 6b/7a western Maryland/Cumberland Valley. Rain?? What’s that?
Holding up well on their own: baptisia, orange tiger lilies, goldenrod fireworks, liriope, common milkweed, variegated Solomon’s seal, iris tectorum, nepeta walkers low, verbena bonariensis, various sedums, dwarf goats beard.
Failing without water: all other perennials, including black-eyed Susans and coneflowers.
Annuals: alive only because I’m watering them.
Pots &hanging baskets being watered a minimum of 2x daily.
Established shrubs are holding up ok, except rhodies and hydrangeas (however, oak leaf hydrangea in ground 12+ years NOT needing supplemental water, yay). Black lace sambucus? Growing like a bad weed (does anything slow this shrub down?)
All established trees dropping leaves.
Veggies in raised beds and growbags looking like heck! Peppers not growing at all, tomatoes have blossom end rot, beans blooming but not setting fruit, zucchini not growing at all (!!!), … I can’t go on, its all too depressing. And where oh where are the pollinators??? Disturbingly sparse!
And top it all off with our (usually welcome) constant breeze, which is sucking the life out of so much, and there you have it .
Shudder to think about the upcoming water bill. Not sure if I feel better or worse having outlined all this…
We live in the foothills of the Oregon Cascades and are watering our last winter plantings of several Western Red Cedars, native Ninebark, Goatsbeard, and Indian Plum weekly. Newly planted draught tolerant rock garden can’t be ignored either. Soaker hoses are in beds that are used every 8 to 10 days. When the temp hits the mid 90’s and above more often. Tomatoes are on a soaker and are watered about every 5-6 days. Our wetland area gets no additional care. We try to keep our water usage down. Maybe if I could stop planting it would help !
Zone 7a – Conifer Garden – My Experience
Conifers – in general if established I do not monitor except:
Miniature Conifers (small root systems are monitored closely. Do not go digging near the roots but check around the tree in a few places 4 inches deep) pay attention to firs, spruces and cryptomeria in particular). If in trough or container move into shade with possible.
If I planted tree 4 or 5 weeks ago and it looks like drought will continue I pull, repot and place in shade for summer and replant in fall.
Always check the Thuja! Frequently.
Dwarf Conifers not established – I check every few days particularly Abies, Picea Abies, and unusual species. Abies from hot areas ( pinsapo, momi, cilician, and numidica) do much better than colder cousins.
Surprising drought tolerance – Sciadopitys cultivars, metasequoia and taxodium.
Surprising drought intolerance – dwarf picea omerika (Serbian) and many of the countless dwarf Picea abies. Oriental spruces do quite well in drought.
Excellent drought tolerance – Cedrus (libani, atlantica great. Check on the deodara. Most Pines like it hot and dry in my experience as do junipers.
I check the Picea glauca and Picea pungens frequently if not established.
Alaskan cedars are watched closely and usually require supplemental watering.
I’m sure I left a few out. What to do if soil area is dry around a dwarf conifer? Hand water deeply and make sure the foliage has a chance to dry before nightfall.
That’s so helpful. Thx!!
Left out the Chamaecyparis obtusa. Most do quite well and are drought tolerant when established even the miniatures. Delicate foliage (example ‘Fernspray Gold’ or ‘Butterball’ may burn but usually recover).
Thanks for the informative rant, Susan.
Since you asked, I was so pleasantly surprised when a mass of Astilbe chinensis ‘Pumila’ came back! It just handily went dormant during my absence in a particularly hot and dry period. It had been very useful on a slope of highly erodible soil in Zone 4b west of Madison Wisconsin.
Pulmonaria (variegated white leaf), doesn’t die but it surely does let me know when the sun is too hot or it is too dry.
I have 6 rain barrels but only used less than half the water. Mainly for potted plants and plants in a small woodland like area. I set up a drip irrigation system to the barrels that slowly releases water constantly to that area. I did not use a garden hose to water anything except of course a few hydrangeas that started to wilt a few days before we finally got rain in the Baltimore area.
How about a list of what I did not water at all with no problems.
Cornus sericia Hedgerows gold
Ceanothus americanus
Lonicera sempervirens Major Wheeler
Solidago rugosa fireworks
Coreopsis: moonbeam, summer sunshine, zagreb
OSO easy rose Italian Ice
Liatris spicata
Yarrow various kinds
Helianthus Lemon Queen
Healianthus maximillani
Pycnanthemum muticum
Antennaria plantiaginifolia pussytoes
Salvia yangii (Russian Sage)
Muhlenbergia capillaris Pink Muhly grass
Lindera benzoin
Lavender munstead
Chrysogonum virginianum
Polygonatum odoratum ‘variegatum’
Abelia
Epimedium sulphureum (I have thousands? in a row, along a fence, that are keeping the English ivy from creeping into my yard from the neighbor’s yard – and it works. Plants fighting plants)
Sisyrinchium angustifolium Suwannee blue eyed grass. Even the 50 or so divisions that I made from a large clump all survived and look good even though they were watered only a couple times with minimal water from a rain barrel.
The absolute winner in the dry heat: Ruellia humilis. Planted just 6 weeks ago it was watered once when planted. I was more worried about too much water. The soil was so dry around it that it cracked, and yet, this plant looked like it had been watered every day. It put out its first bloom a day before it rained. Now it has many blooms and is supposed to bloom all the way to frost. They way it looks I will never have to water this plant.
I’m in coastal Maine 6b and when there is no rain and temps go up I water about once a week, more often for new plantings [and I always have new plantings]. I have a small garden but am on a well-draining slope so the hose and I are well acquainted. No summer vacations for me!
In my soil (clay), I can’t always get fingers to a 4″ depth easily/quickly, so I find a soil moisture probe/monitor to be useful. I recommend anyone in a truly dry-summer climate get one. They’re not perfect, but they are much better than NOT checking the soil at all, which I suspect I would neglect to do much if I didn’t have a probe that made it quick and clean to do. They also make it easy to check at multiple points and in areas where you’re worried about damaging roots. I’m less likely to upset a plant with thin probe than with digging around.
Great idea!!
The soil probe id really necessary for me. They are quite inexpensive and can be used for moisture, light, and pH.