Growing in Straw bales
The growing of crops in bales of straw was originally developed by commercial growers in the 1960's, mainly for tomatoes and cucumbers.
It is also an excellent method for amateur gardeners.
Good results can be obtained both indoors and out with tomatoes, cucumber and some more exotic crops such as chilies, melons, and peppers.
The principle behind the technique is that decaying straw generates heat and carbon dioxide gas both of which are beneficial to plants.
Other benefits are:
The heat emitted extends the growing season.
Watering is easier, the good drainage makes it less likely to overwater.
Plant roots grow unchecked.
After cropping the bale can be composted for use elsewhere in the garden.
There are few possible disadvantages:
Where possible, try to use organically grown wheat straw as this will not contain any herbicide residues.
Barley and oat straw decompose much faster than wheat straw, and hay has a tendency to go mouldy.
If growing indoors, place a pvc membrane under the bale to prevent the roots growing into potentially diseased soil, this can also help to preserve moisture.
Watered bales are very heavy to lift, so place them in their final growing position before treatment.
Water the bales several* times over the next two or three days.
*The amount of watering required will depend upon the dryness of the straw.
Bales ready for Preparation
Next apply 175g (6oz) of a high nitrogen fertiliser such as dried blood or sulphate of ammonia to the top of each bale and water in.
This will start the fermentation process within the bale, and heat will gradually be generated.
To speed the process up, maintain a temperature of around 10°C (50°F).
If using this method outdoors covering the bales with old compost bags or black polythene will help to retain heat.
After a few days remove the covers and check the temperature with a soil thermometer, it should be considerably warmer than the surrounding air temperature.
Add another 175g (6oz) of high nitrogen fertiliser, water in, and re-cover.
Four days later add 350g (12oz) of general fertilizer to the bale and water it in.
Over the next few days the temperature should reach a peak of around 43°-54 ° C (110°-130°F) and will then start to cool down.
Overall the preparation process will take 10-14 days depending on the surrounding air temperature.
When the straw bale temperature drops to 38°C(100 F) spread potting compost approx. 75mm (3") thick over the bale then commence planting.
Plant two/three plants per bale, and carefully water the plants in.
Ensure that the roots have moist growing conditions at all times.
Watering daily is advisable, but unlike traditional growing methods, to miss a watering is not as critical, as the moisture content of the straw is generally sufficient to cover for such an event.
As with traditional methods, liquid feeding should be carried out on a regular basis to maintain nutrient levels within the straw.