Give your soil a treatPosted By: rocket veg Category: Seasonal Tips
My bees are hard at work making honey! I have four hives on the go this year and three of them are packed with nectar which the clever bees are busy converting into wonderful golden honey. The hives are on the edge of Bristol and the lucky bees are spoiled for choice when it comes to flowers from which they can forage – mature trees in the local parks, brambles along hedgerows, urban gardens and allotments. At this time of year, buddleia, which seems to grow everywhere in these parts, is flourishing.
Once this this plentiful bounty begins to diminish, I love to give my bees a late summer treat by sowing Phacelia, the delicate purple flowers with a cluster of long, feathery stamens acting as a magnet for all manner of pollinating insects. Phacelia is one of several crops referred to as ‘green manures’, best dug into the ground before it runs to seed or you may struggle to control rogue plants appearing the following season. If you sow later in the year, the plants may survive over winter if the weather is mild and flower early in the year to brighten dull days in spring.
Why sow green manures
There are several significant benefits to sowing these clever crops. If left as bare soil, that patch of ground where crops recently grew will soon be covered in voracious weeds which will leach any remaining goodness from the soil. Covering unused spaces with a weed retarding membrane will do the job of suppressing weeds but will add nothing to the soil, so try sowing green manures instead. Given the right conditions, the seed should germinate quickly and the seedlings will soon put on rapid growth, crowding out weeds and providing a wonderful habitat for beetles and other helpful creatures.
Some varieties of green manures belong to the pea and bean family (legumes) and have the additional benefit of collecting nitrogen, a valuable plant nutrient, from the air and storing this (‘fixing’) in their root nodules. Other varieties of green manures help to break down heavy soil and add humus to prevent soil erosion.
What are green manures?
The term ‘green manures’ applies to a group of annual plants which benefit the soil in various ways, similar to the result of digging in animal manure. Green manures have the advantage of being fast-growing – hence their use as ground cover. Broadly speaking, green manures fall into two categories, for sowing either in late spring through the summer months; or sown in autumn for winter use.
Sowing and growing Phacelia
Sowing Phacelia is very simple. First clear the ground of any remains of plants, lightly forked though the soil as you go. Then scatter the tiny seeds as thinly as possible and gently rake the area to ensure the seed is dispersed. Water well and make sure the soil does not dry out while the seed germinates – which won’t take long at this time of year.
Unless you want the benefits of the flowers – very decorative as well as a real draw for a variety of beneficial predators - cut the plants at ground level before flowering and dig into the ground, turning the roots in as you go. As the remains of the plants rot, they encourage worm activity and rich organic matter will be added to the soil. If you are in a hurry to use the area for new crops in the autumn, make sure that the remains of the Phacelia have rotted before sowing new seed.
Other green manures to try
Crimson clover is best sown in light soil from March to August and left for two or three months until it begins to flower. If left, all manner of bees will make a ***line (!) for the crimson flowers.
Field, or Winter beans are ideal if you have dense soil which needs breaking up. The beans have the added benefit of being a nitrogen fixer and are best sown from September to November and dug into the ground before they flower.
Winter Mix, a combination of Grazing Rye and Winter Tares, is good for sowing in most types of soil and is another nitrogen fixer.