A row of asparagus growing out. Take no spears at the end of the first year, 10% in the second, leading to about 30% after a few years.
The plant consists of the shoot, a rhizome, from which buds grow and roots. It is these roots that are opened out on either side of the ridge when planting. Better pic to follow.
A row of 10 – 15 plants keeps you in asparagus.
Asparagus plants die back to soil level in the autumn and come again in the spring. It is these shoots that peep above the ground that we eat. Asparagus will stay in the ground for 15 – 20 years, and so the spot needs to be carefully planned and maintained, and it takes a while to get the crop established.
For best results, although it will grow in any old soil, plant your asparagus in sandy, slightly acidic soils. It isn’t much use in clay but loamy soil is good too. If it is really heavily clay, then try a deep raised bed with plenty of compost worked in. Add lots of good compost, preferable to rotted manure – partly because you cannot be completely sure about how well rotted the manure is, and compost is frequently better structure.
Though it is possible to grow from seed, most growers of asparagus start by planting year old crowns in early spring.
You should incorporate lots of compost into your soil in the autumn, a good place for your spent grow bag material – without the roots and plenty of new stuff. From here you then have to dig a trench about a spade wide and a spade deep. In the middle of the trench make a ridge out of the compost – it looks like a long pyramid a few inches high.
The crowns should be placed along the trench, roughly 45 cm – 1 metre apart, then cover with soil so only the bud is visible. Cover with more compost – good quality stuff, and water well. The further the distance between plants the heavier the crop you get from the plants. You can plant shallow rooted crops between widely spaced plants, such as lettuces.
Most people plant at around 45 cm to give the plants structural support to each other.
They need to be kept moist but not wet. How out any weeds and keep them mulched if you can. Add rich compost in early spring and again after harvesting, but do not over feed. Support early growth with canes and remove any weeds as soon as they appear.
In autumn, cut them back to soil level and burn the foliage, to be sure asparagus beetle is not in the compost heap.
You need to get plenty of reserves into the plant before taking any spears. It takes about 3 years to start them off, and then in year 4 only take a few spears, then a few more the year after and then year on year about half. Cut spears singly, using an asparagus knife if you can get one, but a long bladed knife that slips under the soil, when they are as tall as your hand.
Asparagus beetle nibbles away at the plant – as well as slugs etc. Tidying the leaves away in autumn helps. On the whole you can pick them off by hand, but if you need to – spray with organic insecticide.