Warmer weather has started to settle in here in the Mid-Atlantic and many of
my vegetables and flowers that were sewn inside will need time to acclimate to
the elements before being transplanted into the garden. This process is
typically referred to as “hardening” and I will admit, I struggle
with it. This year has been my most successful to date, so I thought I’d share
some tips from my previous (and sometimes failed) experiences.
1 – A small temporary greenhouse is a useful tool, but it is not immune to
extreme temperature fluctuations. That’s right, if it gets down into the 30’s
outside then it’s going to be quite cold in your greenhouse too and you can’t
just keep it zipped up during the day hoping to capture as much heat as
possible to get you through the night because, if it’s too hot, your plants
will bake. Literally. If plant cells overheat, the enzymes responsible for
regulating photosynthesis and respiration are rendered dysfunctional and your
plants will die.
2 – Just because it is warm and sunny does not mean that your plants are
wind resistant. A light breeze has the potential to make your plants stronger
by encouraging robust stem development, but you’ll want to avoid starting the
hardening process on a particularly blustery day.
3 – The sun. If your seedlings do not get direct sunlight indoors they will
be even more sensitive when placed in a full-sun environment outside. You may
see areas where the leaves become translucent and blister due to intense UV
exposure. A good method for adjusting to the sun is a gradual process. Start
with an hour outside, then bring them back in. The next day try 2-3 hours and
gradually work up to a point where your plants are spending all day in the sun.
I know it sounds tedious, but you’ve worked so hard to grow those beautiful
babies up, you don’t want to lose them now. They’ll be worth it!
4 – The dirt. If you have chosen to supplement your soil you will want to
let it sit at least a few days before you put your plants in. The intensity of
the various compounds in fertilizers can be extremely hard on the root systems
of your plants. Let it diffuse into the soil and dilute a bit to prevent root
damage. Additionally, if your seedlings have a well-developed root system it
may seem as though they are invincible. They are not. If your roots experience
too much damage during the transplanting process, whether it be due to breaking
up the root ball, trying to remove the plant from the pot, pulling plants that
shared a pot apart or over fertilizing, your plants will struggle to adjust.
They will have to repair and/or replace damaged root systems and if they
recover it can take a significant amount of time and push back your growth
season. Be gentle.
5 – Give them a drink. The small amount of soil directly surrounding the roots
may be wet but if the ground or potting medium is dry then that moisture will
disperse into the surrounding soil and may become less accessible for your
young plant. Providing additional water will minimize this effect.
Some of these may seem like common sense but when you’re excited that Spring
is finally making an appearance it is easy to get caught up in the moment and
become mildly overzealous. Patience is critical and I possess very little so I
have learned all of these things the hard way. I hope that my growing pains
(pun intended) will help make your hardening process a little easier. Cheers,