One of the hardest things to do in gardening is knowing how
to water correctly. There are many different variables that will contribute to a plant’s drinking
rate. Some of these affecting variables
are: size of the container, what the container is made of, drain holes in the
container, air space, wind, sun, shade, temperature, growing medium, and the
size of the plant.
To start off, we want to make sure that our plants are
potted correctly in the selected container.
I’ll do another blog in the future on potting correctly. The main point here is that the soil line
should stop below the top of the container leaving a space from the top. This space that is left contributes to the
plant being watered correctly. If the
soil level is too high such as being level with the top of the container it is
planted in, the plant will never get watered correctly and the risk is higher
for the roots to start growing near the surface due to the water hanging out at
the top layers of soil. In turn, these
roots, instead of being well beneath the soil surface, are now at risk from
being burned by the sun.
So we know where to bring our soil level to. But what kind of soil do we use? Or should we
use a soil-less mixture? The consistency
of the growing medium will affect the plants drinking rate. I prefer to use non bark soil-less mixtures
when planting annuals in containers.
Bark mixes are too acidic and will eventually turn the foliage on the
annuals to a yellow color. However, douse
bark mixes for perennials.
Soil-less mixtures are much lighter than your typical garden
soils. When bone dry, a soil-less mixture
is super light like dust; one could sneeze and it would blow everywhere. This has its advantages. A soil-less mixture will go from being fully
saturated to drying out in a much quicker time frame than a garden soil. If you are liquid feeding, one could
incorporate this after every two wet/dry cycles of the container. So look at it this way…if you are setting your
potted container in an area that may be slightly shaded, not too windy, not too
hot, go for the soil-less mixture. It will dry out quicker and lessen the risk
for CROWN ROT from being too wet for a sustained period of time. If the container is perhaps on a roof top—the
weather can be very hot and windy which will speed up the plants drinking or
dry out the soil much quicker. You may
want to use a mix of a soil-less mixture with a garden soil. Garden soils will hold onto their water much
longer.
You have to be very careful with garden soils though. Because they can be heavy and sometimes clay
like, a soil-less mixture trumps it. For
a plant to get bigger, its roots prefer a growing medium that allows the roots
to easily spread and grow..not struggle in the environment of a heavy clay
soil. Growth can then be very stagnant
or halted. The risk of over saturation
runs high and your plant(s) remain water logged for days. Not good.
The container size should carefully be selected. Like knowing your child, learn to know your
plants. They all have different drinking
rates, especially when at full growth.
I’m not going to take a 2 inch Petunia plug and plant it in a container
that has a diameter of 30 inches. It
would never get watered correctly. The
container would either stay wet for a prolonged period of time or dry out from
being under watered.
After having a good idea of your plant’s drinking rate and
the size container it will go in, the ideal to strive for would be to have the
container go from being fully saturated to almost bone dry in 2.5 days max.
Keep in mind that clay or Terra Cotta pots will also affect the water rates as
they absorb water! Wind, direct sun,
circulating air all diminish or quicken the drying out rate!
Now here is the key, when it is time to water, one should
fully saturate the container—this means the growing medium should be fully wet
from top to bottom. If a soil-less mixture
is being used, notice the weight difference when wet verses bone dry. Also note that if the container accidentally
dries out, soil-less mixtures will have to be watered a few times in sequence as
the first two times, the water will run right out of the container…remember
full saturation.
Now if we lined up our marbles correctly (is that how it’s
said?..I’m still young and don’t know those old sayings) the container should
be almost dry in 2.5 days. At that
point, we can fully saturate the container again.
Don’t fall into the trap of “oh I have to water everyday”
just because the plants is there. If it
is an overcast cloudy day, DON’T WATER.
There are no high demands being put on the plants. Watering on overcast cloudy days just
increases the risk for BOTRYTIS and CROWN ROT.
Now if our containers were clear and see through, this would
all make better sense. When fully
saturated, one would see the saturated soil.
As the water gets used up by the plant(s), one would be able to see
this. Mistakes are often made when “the
grower” notices the top, say 2 inches of the container’s soil line is dry. More water is then added and creates over
watering because “the grower” failed to detect that from 4 inches to the
bottom, the container was saturated.
Also when watering, don’t water like a madman. I often see many practically killing their
plants from the stream of a garden hose that is too much. Water at the soil line. Flowers can get bruised and discolored from
water. Additionally, petals get knocked
off, fall and stick to the foliage which starts to create that wonderful
environment for BOTRYTIS.
Incorporate your liquid feedings whenever. Just make sure that your container is fully
saturated first. I’ve played with some
super phosphate ferts mixed at high ratios and always had desirable results.
