In my last
newsletter article I talked about some general post-harvest handling of
summer crops after they had been harvested from the field. Now that
fall is here and storage crops are coming out of the field, I thought it
may be helpful to discuss how to get the most
of these. With winter markets becoming more and more common, there has
been a renewed interest in growing storage crops for direct sale
throughout the winter. Curing and storage of these crops can make a big
difference in quality throughout the winter months.
We grow a
lot of potatoes, both because I love to eat them and I think they are a
lot of fun to grow. One of the things that I think is really neat about
them is that you are the first person to ever see them when they are
getting dug. It is a lot like a treasure hunt, and who does not like
finding a surprise every once in a while?
potatoes are growing, the skins are very thin and fragile, and are not
suitable for long term storage. The skins need to be set before they are
ready to dig. The death of the plant sends a signal to the potatoes to
go dormant. You can either let the plant die naturally, or do what’s
more commonly done, kill the tops. Conventional growers typically do
this with a chemical that kills and desiccates the tops. Organic growers
have different options. We lop ours off with a weed whacker. It takes a
little time, but does a better job than a mower. I have never gotten my
mower to work well for this purpose. Another option is to flame the
tops off, but depending on the health of the plants it may take more
than one pass. One consideration is that when you are trimming tops or
mowing, you are also creating millions of injuries that can allow the
spread of disease. We always time our topping so there is a long stretch
of hot and dry weather, this ensures plants wounds will dry quickly and
lessen the chance of infection. After the tops are removed, a minimum
of two weeks is required for the skins to thicken. I wait a third just
to be sure. Then they are set for harvest and long term storage.
dig them, we leave them on the soil surface just long enough to have the
skins dry. We then put them in bushel baskets in our “cold room,” an
insulated room next to our cooler. I allow cool air in at night time to
keep the temperature at 55- 60°F for 3-4 weeks. This gives the potatoes a
chance to heal any bruises or cuts that happened during harvesting. For
long term storage we lower the temp to 38°F. We have used a root cellar
that also worked well, but found the physical moving of potatoes was
not very fun. Now we move them in and out of our walk-in in the barn,
which gives us much more time and energy to eat them!
harvesting of onions is also subject to the condition of their tops. It
is important for the tops and necks to be as dry as possible before
they are topped and brought in. Some varieties that have thin necks down
really quickly and can easily be pulled from the bulb. Unfortunately
the ones I choose to grow do not do this easily. I have had problems
with Alternaria and Botrytis in my onions for some time, so I choose
varieties that have really good resistance to these diseases but may not
dry down quickly or have thin necks. My experience is that they also
hold onto their greens longer than most varieties too.
growers simply let their onions dry down in the field and come through
and top as they harvest. You can also undercut the bulbs several days
before harvesting when there is only a few green leaves left.
Undercutting speeds dry down and will improve storage quality but relies
on special equipment. Due to my particular situation I do things a
little differently. I invariably walk the patch and push over the necks
with my foot to encourage them to finish up. I seem to never get the
weather I need for them to dry in the field either, so I bring them into
a greenhouse and lay them on the benches a few deep to finish drying
down and top them here. It’s extra work, but it feels like it pays to
have them where I have more control. I keep them in the greenhouse for
five or six weeks, ensuring they are well cured, and then I put them in a
cool and dry spot for the winter in mesh bags. Be sure to gradually
decrease temperatures, if decreases too quickly or fluctuates
significantly it can cause bulb staining, sprouting or decay. Ideal
storage temperatures area as close to 32°F as possible with out
freezing at 60-70% relative humidity.
Carrots and Beets
always the question of wether to wash or not to wash carrots and beets
before storage. We store ours washed for two reasons. The first is that
my barn is really a three season barn, and is pretty cold in the winter,
making washing very uncompfortable. I also have better luck getting
them really clean when they are first out of the soil as the soil can
stain carrots. If you can keep the humidity high enough, the soil won’t
stain the carrots as much, but I just assume get them done in the fall.
and beets will store until the spring if kept cold enough. Store them in
vented plastic bags at 34°F till spring. It is commonly said that you
can not store washed carrots longer than 6 or 7 weeks, but we kept ours
into the next season, and they did fine. I was super picky about what
went into storage, and anything questionable was set aside for earlier
who bring in carrots and beets and store them dirty, there are a few
considerations. First, it is important to make sure that they are cooled
quickly. Bringing in tons of unwashed, warm roots can overload the
capacity of many walk-in coolers. A local grower I know leaves his bags
outside on a cool evening and picks them up in the morning before the
sun comes out. This way he is leaving a lot of the field heat outside.
The other piece is to stack the bags in a way that allows for air flow
around the pile. A heap against a back wall will have a core that takes a
long time to cool down, and those roots will degrade quicker. Misting
the stacks with water will help keep the humidity up, and make them last
longer and be easier to clean.
We have had good luck storing
Napa cabbage in the
cooler for long stretches as well. They keep at 34-36°F and have had
them be beautiful after stripping the outer leaves 5 months after going
into the cooler. The same with red and green cabbage. Clean them up
before they go into the cooler and keep them cold.
squash is one of my favorite things. I look forward to it for at least
the second half of summer, and enjoy it well into the winter. Curing the
squash is important, not only for flavor but also for storage. We use
our greenhouse again, keeping them in there for at least two weeks
before we bring them to market. I keep them in the greenhouse until late
fall, and then move them into a cold room, which we keep around 50°F
and a relativehumidity of around 50-60%. I keep checking them, and I eat
them as they get a bad spot. They can suffer injury at temperatures
below 50 F, so be careful with the temps.
hope that this season has brought you loads of good food for your
families and customers, and that a well deserved rest is on the horizon.