plants have a productive life of around 8 to 20 years so are a great value crop when you consider the price of shop bought asparagus. Of course, the downside is that you have to commit one area of land to the same crop for up to two decades! Not a problem if you have a large garden but if your veg growing is confined to containers and raised beds then this is not a crop for you. It’s not for the impatient either as you will have to wait two years before you can start to harvest. Having said that, once planted, asparagus is an undemanding crop that requires only basic care and maintenance.
Soil & Growing Position
The main soil requirement is good drainage so a free-draining soil is essential. Pick a sunny spot, ideally protected from strong winds. During the autumn/winter prior to planting, dig in plenty of compost or farmyard manure (See Soil Preparation). Test the soil to check it’s Ph levels and dig in some Lime if it is very acidic. Try to thoroughly remove any perennial weed roots whilst preparing the soil. In the spring fork over and rake in some Growmore a week or so prior to planting.
Sowing from Seed
Whilst you can raise from seed, it is easier and quicker to plant one year old ‘crowns’, otherwise you will need to wait three years before regular cropping can begin. Sow in April, thinly in a seed bed, in drills 1” deep and 12” apart (See VegGrowing from Seed). When seedlings are 3” tall, thin to 6” and plant out the largest plants in the following spring.
Growing On & Young Plants
If you have bought asparagus in it’s ‘bare root’ state, rather than potted in soil, ensure the roots do not dry out. Plant out in April once the cold and wet weather has passed. Plant the crowns 12” apart, in trenches dug 3 feet apart. Trenches should be 8” deep and 12” wide. Spread the roots out when planting. Cover the crowns with a couple of inches of (sifted) soil straight after planting and continually fill up the trench gradually as the plants grow. By autumn the bed should be level. If any berries appear on the plants, these should be removed.
Weeds can be a real problem in asparagus beds so really try to keep on top of them as they can quickly run out of control. Hoe carefully between the rows but the rows themselves will have to be hand weeded so as not to cause any damage to the growing spears. The rows will only need watering during really dry spells.
Slugs can be a real problem as they gnaw at the young shoots when they are barely visible causing the developing spears to become twisted and deformed. It’s best to anticipate this and use slug pellets from early on in order to stop it from happening.
Asparagus beetle, distinguishable by it’s orange markings on a black body (approximately half a centimetre long) will need treating with a insecticide as soon as it appears, before it causes damage to the roots.
‘Wind rock’ loosens the plant’s roots, resulting in rot and is caused when plants are in a windy spot and are not properly supported. Use wind breaks around the veg patch or use canes along the rows with string to provide support to the plants to prevent this from happening.
Any severe frosts in late spring will cause young shoots to turn black and die. Simply remove the affected spears and destroy. You can put fleece or sacking over the rows if a severe frost is forecast to prevent this from happening.
If reddish brown spots appear (‘rust’), remove and destroy any affected foliage as soon as the spots appear as control of rust through spraying can be ineffective.
After harvesting, allow the fern to develop and do not cut down until they have turned yellow in the autumn. Then cut to leave stumps approximately 1-2” high.
In late winter/early spring, prior to the first spears appearing, use a draw hoe to make a ridge over each row and apply a dressing of Growmore to feed.
Shortly after planting, some spears may appear but these are to be left and allowed to develop into foliage. The following year it is best to leave the plant alone again although some sources say a small cutting, one spear from each plant during May, will do no harm. Harvesting begins the following year, the second year after planting. Spears should be cut when they are around 4 to 5” tall and cut a couple of inches below the soil surface using a sharp knife or asparagus knife. Spears should never be left to become tall, cutting every day if necessary. Stop cutting in early June, mid June at the latest and allow the final spears to grow and develop into ferns in order to reenergise the plants for the following year. Don’t be tempted to carry on cutting as prolonged cutting will only lead to thin, spindly spears the following year.