Plant crowns now for 15 years of asparagus

20:16, Aug 05 2012
PROLIFIC: Male crowns will produce more asparagus than female crowns.

Asparagus is a popular seasonal vegetable that is easy to grow, in a well drained situation.

Asparagus crowns are available in your garden centres now and these are the root systems of 1 to 2-year-old plants. The newer hybrid varieties such as Jersey Giants, all male crowns, will out produce the old Mary Washington crowns three to one.

Female crowns do not produce as many spears as the males and will produce seed berries when in fern. I presume that the crowns for sale are male, but it would pay to ask. The odd female crown may be present, but you can remove any stray females and replant a male.

In establishing an asparagus bed you have to consider that for a good part of the season, when the spears are allowed to go to fern, the foliage could shade other plants. Thus a bed or row should be placed at the rear of a vegetable garden where it will receive ample sun, be free draining and be in production for about 15 years. The crowns should be planted about 45 centimetres apart.

Half a dozen crowns, once established, will give you about 1 kilograms of spears each season.

There are several things to do to set up your asparagus bed. A single row down the back of the vegetable plot facing north would not take too much room and other tall plants, such as corn or tomatoes, reach their heights later in the season when asparagus spears have been harvested.


Make a trench or bed 12cm-15cm deep, which is the depth you plant the crowns. Work the soil at the base of the trench/bed to make it loose and friable. Place one scoop of BioPhos under each crown. Lay the crowns onto this and cover with a mix of animal manure-based compost with the soil removed from the trench/bed at a ratio of 50/50. Fill to the level of the surrounding soil. Ensure that this mix is open and friable, not heavy and wet.

The crowns can be planted now although they will not grow till the soil warms up, but it is important that the area is free draining as waterlogged crowns will rot.

When the tips of the first spears emerge you can enhance the conditions with an application of potash and then a drench of MBL (Magic Botanic Liquid) and Mycorrcin mixed together. In the first year do not pick any spears to enable the crowns to establish and grow. The more fern means the more growth to the crowns. Keep the bed weeded.

In autumn/winter when the ferns have died, cut down and if you have access to seaweed cover the row/bed with this for the winter. It makes for great asparagus. Weed as needed.

To harvest, on the second year onwards, do not cut the spears off below ground level as this can damage other spears coming. Instead snap the spear off at the base.

Another spear will emerge in its place from another growth tip. Harvest for about three weeks but towards the end the spears will begin to open and become tougher at the base. Then allow the plants to go to fern. Always pick spears early in the morning.

To store, put freshly picked spears into ice cold water and then put into a plastic bag and place in the fridge. They will keep this way for one to two weeks.

Problems? Phone me on 0800 466 464 or email

The Southland Times