By
Kimberly Warren
Associate Editor
When looking for ways to improve their growing conditions and the
control of them, many growers turn to the greenhouse – especially
when it comes to strawberries. The disease pressure is less, the harvesting
is easier during rainy weather, and the environment can be more easily
controlled. But what if there were a way to improve those indoor environments
even more?
For strawberries, there is: soil-less, table top – or similar
– system.
“Basically, it involves growing strawberries in containers in
a substrate other than soil,” said David Simpson, of Horticulture
Research International, East Malling, United Kingdom (UK). “Peat
is the most common, but there are others such as coir and composted
bark. Containers are normally either grow-bags or 2 gallon buckets.”
This system, Simpson said, is normally used with 60-day plants, though
everbearers could be used. And the system works better using an annual
system because plants do not perform well if left in the bags for
a second year, he said.
“This system has three principal advantages,” Simpson
wrote in his paper presented at the Great Lakes Fruit, Vegetable and
Farm Market Expo. “Firstly, the artificial substrate eliminates
soil-borne diseases and give the grower complete control over plant
nutrition. Secondly, the containers can be placed at a convenient
height for harvesting, thereby improving picking speeds and reducing
costs. Finally, the system is flexible – containers can be moved
in and out of the glasshouse to make it possible to produce three
or four crops in a year.
“Picking strawberries is never a very popular job because you
get back ache,” Simpson said. “It is very flexible, as
the bags can be moved in and out of a glasshouse or tunnel for programmed
production. It allows an extra crop per season to be achieved in the
same area of a glasshouse or tunnel.”
But, not all varieties will work well for this system.
“It works best with the less vigorous varieties that have a
fairly compact habit,” Simpson said. “The optimum growing
conditions are the same as for soil-grown strawberries, but because
it is done under tunnels or in glasshouses, the grower has more control
over the conditions and can extend the season at both ends.”
Though this system is popular in Holland, Belgium and the United Kingdom,
it has yet to catch on in the United States.
“It’s certainly not being done in California or Florida,
which are the main areas where strawberries are produced,” Simpson
said. “It’s possible. There’s no problem with using
this system anywhere in the world, really. If you’ve got a climate
where you can grow strawberries, then you can use this system.”
One of the difficulties may be that nurseries in the United States
don’t often provide the types of plants needed for this system,
Simpson said.
In addition, the system is expensive to get started.
“You’ve got extra costs for paying for peat, bags, and
plants are more expensive to buy in the first place,” Simpson
said. Add to that the costs of the materials used to build the structures
to put the strawberries on – straw bales, tubular steel or timber
– and the costs rise. Plus, there are grow-bags specially designed
for producing strawberries in this way. The bags would either have
to be imported or produced locally with pre-set specifications.
“It is more costly, but not necessarily less profitable,”
Simpson said. “I know quite a few growers in the UK who have
started using this for pick your own. In fact, as with the commercial
pickers, the people who come to pick-your-own farms, they pick more
quickly and therefore buy more fruit.”
For growers looking to start this system, Simpson has some advice.
“Start on a small scale and try different varieties to see which
works best.”
