Investing in a greenhouse in Kenya is ideal in order to protect plants from extreme weather conditions. One can either build one or invest in a ready-made one.
A small greenhouse or shadehouse in the garden is very useful to have, especially if you want to grow plants that need the extra protection from the sun, wind and rain or if you are just looking to increase the daily temperatures and humidity for the plants.
If you live in the cooler climates, above 2,000 metres altitude in Kenya, there is even more need for a greenhouse. Rain, not that we ever have much of it nowadays, would cause a problem when rooting cuttings of succulents, so they would be better protected in a greenhouse.
We see more small scale farmers in Kenya today are using greenhouses in which they can provide better protection for growing their crops of tomatoes, courgettes and some cut flowers.
Where Should I Construct My Greenhouse?
Level ground in a sunny position would be ideal. In a greenhouse it is easy to control shade, but in a shady location it is very difficult to increase the amount of light. A location where there is dappled light for part of the day would be alright but avoid deep shade under trees.
Gently sloping ground would be alright but steeply sloping ground would need the roof and the floor inside the greenhouse to be stepped, which just adds problems.
Also consider the direction of the prevailing wind so that the roof structures openings face away from the wind to give good ventilation and avoids the rain beating in during times of a downpour.
Advantages of Greenhouses
Little space needed
You need as little space as the one in your backyard. I put two of the green houses in the compound of my fenced-off house. This space is normally left idle in many homes.
Controls Pests & Diseases
Greenhouse farming curbs most pests and diseases. It is difficult for pests to invade greenhouses because scientifically, most pests move with either water or direct sunshine, but since the structure does not receive any of this directly, pests are kept at bay. My own experience shows that although I planted the tomatoes 10 weeks ago, they have not been affected by disease.
High production rate
Your crops can yield 100 times more than those grown under open or ‘normal’ conditions. While tomatoes grown in the open yield 40 tomatoes, green house tomatoes can yield up to 200 tomatoes of an average 120g.
Since crops grown in green houses depend on irrigated water, you can harvest the commodity at any time of the year. In other words, you can turn it into a full-time job.
Crops grown in green houses are much cleaner compared to those grown in the open that have scratches, hence lowering their market value.
Multiple harvest times
Tomatoes grown in greenhouses can be harvested three times longer. For instance, I will harvest tomatoes for the next 10 months.
You can farm anywhere because their growth does not depend on the surrounding environment.
Use local materials, especially for the basic role of holding the special polythene sheeting together.
I use eucalyptus poles to construct the main frame, on which I have covered the special polythene setting.
In simple terms, a 15×8 metre shelter costs not more than KES 70,000, including labour and an irrigation system.
However, the cost may increase to at least KES 80,000 if you include the seeds, fertilizers and pesticides. Also, look out for seeds specifically created for green houses.
It is Cost-Effective
People generally think greenhouse farming is too expensive. However, what actually seems expensive is the initial investment in buying the materials for the structure. However, these expenses are easily offset by the high yields that a farmer makes from the investment. For example, in 10 months, a farmer will averagely harvest 10 tonnes of tomatoes from a 15×8 piece of land. At the current price, a kilogram goes for KES 50.
If the initial investment was KES 70,000 including the drip irrigation system, with his yield, a farmer has recovered the investment in a year and got good profits. The materials that make the shelter have a lifespan of at least three years.