Creating a Drought
involves much more than simply choosing drought tolerant plants. Our
well-intentioned habit of watering the garden too often should be corrected to
create a healthier garden that simply doesn't need our watering help to thrive.
Here's an article I wrote a few years ago that will help
you work towards a healthier and more Drought
THIS SUMMER WE'LL
by Evelyn Wolf, 2002
out at midnight with a watering can to your perennial beds during a water ban is
not the time or way to protect your garden from drought. Spring and early
summer is when to prepare your plants for the inevitable heat and drought of
high summer by training them to send their roots deep through smart watering
Early in their life, all plants benefit from
being taught an important life lesson - how to stretch their muscles and
work for their meal! In these days of a heightened consciousness about
water conservation, there can be no more express room service
delivering water at the first sign of a dry weather.
In our hurried lives, we often
take a bit of time every few days and give the garden a quick sprinkle with the
idea that plants, like children, need our constant nurturing. Many people
install irrigation systems and set them to come on every day to make this
easier! But plants past their first few months are not children - they are
fully mature adults that know how to look after themselves, as long as we let
them learn how. Constant moisture at the soil surface through frequent
watering not only makes plants lazy, it is actually harmful - promoting
mildew and fungus diseases like black spot and powdery mildew, and worse - an
unnaturally shallow root system which makes them that much more ulnerable to
drought. (Worse yet - weed seeds sitting at the soil surface have the
opportunity to sprout like crazy!)
Plants aren't stupid!
They know that water is essential to life, and they will work hard to find it.
All plants naturally reach for wherever the water is, which should be downwards
where all soil is normally cool and damp. When we water frequently and
shallowly, as happens with an irrigation system, roots don't have to reach at
all and instead stay within the top 6 inches of the soil where the soil is made
always moist, rather than establishing a deep root system. Quite simply,
we promote a false sense of security and make them lazy with our pampering.
Under these conditions, it would take just one rainless weekend away from your
garden, or just one failure of an irrigation system, for these plants to show
signs of drought stress since their roots had been trained to stay near the
surface where temperature fluctuations are extreme.
It is far better to not water
at all, and make your plants stretch down for their water. They will be
much stronger having developed a larger and deeper root system, and fully able
to glide through the long hot days of July and August unscathed. Their
roots will be down a good 12 - 18" or
more where it is usually still cool and moist.
When drought is severe, such as we
experienced last year, some plants may be stressed to the point of withholding
bloom or may even enter early dormancy as they try to cope with the lack of
water. However, as with all forms of life, the instinct for survival is
strong and long term survival skills are built into their DNA.
Rather than expend energy on blooming and risk death in a drought,
perennial plants will hunker down and conserve energy by not blooming or
growing. They may even drop or fold up their leaves, with the goal of
simply surviving until they can go dormant for the winter and come back in
spring when conditions are better. If they have been trained to have a
strong, deep root system, they will come back with flying colours.
If they have shallow root systems because of frequent shallow watering, some may
not make it having been stressed too severely in the drought. (If you had
roses and shrubs that died over the past winter, they didn't die because of the
harsh winter, they probably died because they entered a tough winter with a
shallow drought weakened root system.)
Here's some general guidelines for watering your perennial beds -
1) Don't ever water until at least the top 3" of soil is
2) If you feel watering is needed
but only have time for a quicky, don't water at all. Instead, spend
those few minutes you have giving any new plants a good
When you do water your garden, a slow steady trickle right at the
soil level is best. Overhead sprinklers waste a tremendous amount of water
through evaporation (up to 1/3) before it ever has a chance to get to the roots,
and the constant moisture on the leaves promotes disease and rot problems.
I used to devote an afternoon to moving around a little fountain type sprinkler
at a very low pressure setting to really soak any area that needed it for about
an hour. Visualize the root zone of your plants, not the soil surface.
Your goal is to have moist soil at the bottom of the root system and
beyond to encourage roots downward - that means about 12" - 18" down. If
your watering efforts only went 3-4" deep, then that's where the plant's roots
will stay and you've actually done more harm than good.
If you have conditions such as a slope or hard clay which tries your patience,
taking a plastic jug with the bottom
cut out and burying it upside down beside your moisture lovers to deliver water
directly to the root area. Most of your plants will still need to fend for
themselves, but at least you can cater to those few that need your help.
Irrigation systems may be great for lawns but they can mean death for a
perennial garden. They are often on timers set to run every couple of days
for 20 minutes or so. The shallow roots of lawn grass are grateful, but
after a few years your perennial gardens develop a mass of roots at the surface
that is completely vulnerable to constant stress of temperature fluctuations,
and this constant stress leaves them generally weak. The problem
multiplies upon itself once this happens since the thick mass of fine roots that
ends up blanketing the whole soil surface actually starts to either shed water
or hold water like a sponge,
preventing water from percolating down. A few years of this and
your perennials have, ironically, adapted to desert-like conditions where there
is never water held deep in the soil and plants develop their roots in a wide
reaching surface skirt to catch and use every single drop of rain that falls
before it evaporates. If you have an irrigation system, aim the
heads at the lawn only and use soaker hoses (or nothing at all) in your
Perennials in their first year
need some watering help, but an established
perennial garden is actually
better off left to what comes naturally from the sky. If soil is
prepared well with plenty of organic matter in the form of compost, chopped
leaves, or peat moss, roots will have the food to grow strong, and have an easy
run to grow downwards where they're safe. Mulching or using ground cover
plants also helps conserve moisture, but be careful not to pile mulch on or near
the crown. If a serious drought does come, unpampered plants with their
roots trained deep, will be fully able to cope. They'll do the smart
thing by plunging even deeper for water. While we gripe and complain about
the heat, they'll be just fine. A few leaves may get a bit tip burned, but
that's about all the damage I've ever experienced even after weeks with no rain.
In my last home, I established a
garden bed in an area dominated by mature cedars that sucked the ground dry in a
blink. I was determined though, and with persistence, I grew hostas,
bleeding heart, etc. with moderate success. The first year I made sure to
water very deeply once a week. In the second year, I watered deeply only
when 2 weeks had gone by with no rain. In the third year, I watered
only during the really dry times in August - and again, very deeply with a soak
of at least a few hours. Astilbes and some of the hostas just couldn't
thrive in this bed, but many other perennials did.
When I moved and dug up some of
these plants to take with me, I had to go down 18" - 20" before I gave up and
simply cut the roots. They had reached down much more than they naturally would
have in their quest for water. This was a huge teaching moment for me that
gave me the confidence to start trusting that perennial plants know how to fend
for themselves and survive. It was a real "Daahh" moment when I truly
realized that plants are dynamic living things just like us, and that like all
healthy living things, they will struggle with all their power to adapt and
survive - to go to where the food and water is if it isn't near at hand.
Just like us, they won't say "oh well", and just keel over and die!
They'll work hard, and have the DNA drive and know-how to do it.
Now, only real moisture lovers like my Ligularia or the many new plants I put in
each year, get any watering attention from me at all. Dryland lovers
like Flax, Yucca, Artemesia, Lavender and others now grow tight and strong
rather than weak and floppy as would happen in a wet garden, and come back
reliably each year rather than succumb to crown rot. As I visit other
gardens through my gardening services work, it's been my observation that
MANY more plants die from crown rot through overwatering than die because of
drought. Crown rot through overwatering is about the only way
established plants ever truly die.
Perennials are tough as nails
survivors with the ability to live longer than we do! They know how to
struggle through and adapt to all kinds of hostile conditions. When at
least their basic needs are met, they quickly adapt to their surroundings and
begin the struggle for survival. They will adapt to dry hot conditions
by sending roots deep. They will adapt to crowding above ground by
stretching their stems and leaves as tall and straight as they can to reach for
their fair share of sunlight. They will adapt to nutritionally lean soil
conditions by growing tight and compact instead of lush and large. Bottom
line, plants aren't stupid! They know how to survive - sometimes in spite
of gardeners rather than because of them!
My plants are better
than ever for this lesson learned, but I have to confess that I feel a bit
rejected now that I realize that they really don't need me at all once
I've gotten them past their first few months. (Perhaps this is why I'm
always compelled to buy new plants!). I miss that lazy hour at the
end of the day when watering would give me an excuse to linger in the garden.
To accommodate this little pleasure and sooth my bruised ego, I keep a
small patch of moisture lovers in a naturally dry spot just so that I can still
feel needed. It works!