How To Grow Asparagus / RHS Gardening

Looking after established asparagus is straightforward – just weed regularly, apply mulch Mulch is a layer of material, at least 5cm (2in) thick, applied to the soil surface in late autumn to late winter (Nov-Feb). It is used to provide frost protection, improve plant growth by adding nutrients or increasing organic matter content, reducing water loss from the soil, for decorative purposes and suppressing weeds. Examples include well-rotted garden compost and manure, chipped bark, gravel, grit and slate chippings. annually and put supports in place to keep these tall plants from being blown over. At the end of the season, when the foliage turns yellow, cut all the stems down to the base.

Watering

Water new asparagus plants regularly throughout their first summer. Once established, asparagus is drought tolerant, so only needs to be watered in long dry spells. For more water-wise advice, see our guides below.

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Mulching

Apply a thick layer of mulch Mulch is a layer of material, at least 5cm (2in) thick, applied to the soil surface in late autumn to late winter (Nov-Feb). It is used to provide frost protection, improve plant growth by adding nutrients or increasing organic matter content, reducing water loss from the soil, for decorative purposes and suppressing weeds. Examples include well-rotted garden compost and manure, chipped bark, gravel, grit and slate chippings. to the soil each year in late winter to discourage weed germination Germination is the process by which a seed develops into a new plant. It starts with the seed coat absorbing water, expanding and splitting, which allows oxygen and water into the seed so its food reserves can be broken down and used by the embryo for growth. The first root (called the radicle) pushes into the soil to anchor the new plant in place and start absorbing water and nutrients. The first shoot (called the plumule) then grows upwards, out of the soil, towards the light. and hold moisture in the soil. You could also consider covering the soil with biodegradable Anything that can be decomposed by fungi, bacteria and micro-organisms, so it doesn’t persist indefinitely in the environment. Biodegradable plastics are usually made from plants, such as bamboo, rather than fossil fuels. Ideally, products that claim to be biodegradable should break down quickly and leave nothing harmful behind. However, they may need specific conditions in order to biodegrade successfully or may produce greenhouse gases such as methane in the process. weed-suppressing membrane from autumn to late winter, while the asparagus is dormant Dormancy refers to a period of inactivity in plants, during which they slow down or stop their growth, conserving energy and resources. This is a natural process that helps them survive harsh conditions, such as winter or drought. Dormancy in seeds is a mechanism that prevents them germinating until environmental conditions are favourable for growth. , to prevent annual weeds germinating Germination is the process by which a seed develops into a new plant. It starts with the seed coat absorbing water, expanding and splitting, which allows oxygen and water into the seed so its food reserves can be broken down and used by the embryo for growth. The first root (called the radicle) pushes into the soil to anchor the new plant in place and start absorbing water and nutrients. The first shoot (called the plumule) then grows upwards, out of the soil, towards the light. .

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Feeding

In most soils, established asparagus plants should crop reliably without additional feeding, especially if the soil is regularly mulched with organic matter. But, if growth is poor, you could apply a general fertiliser in early spring, before the new spears sprout.

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Weeding and removing female plants

It’s important not to let weeds get established in an asparagus bed, as they compete with your crop for light, water and nutrients, and removing large or widespread weeds can easily damage the shallow roots of asparagus plants. Weed by hand rather than with a hoe to reduce the risk of damaging them.

If you have female plants (which produce orange-red berries), weed out any seedlings A seedling is a young plant grown from seed. they produce to limit competition.

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Supporting plants

Asparagus grows into a tall, feathery plant over the summer. To prevent the stems breaking in windy weather, which could damage the crown, support plants using stakes and twine Twine is a soft, fine loosely woven string treated with preservatives for outdoor use. Used for tying in climbers and other plants to supports. to make a ‘fence’ either side of the row. You could also add netting, secured to the stakes about 50cm (20in) from the ground, for extra support.

Propagating

To fill gaps or extend an asparagus patch, you can divide well-established crowns in late winter or early spring. Do this no more than every three years, as the plants can be slow to settle back in afterwards.

Dig up the crown, handling it carefully. Gently prise it apart into several smaller sections, each with several growing points, taking the strongest parts from the edge of the crown. It may be necessary to cut some roots if they can’t be pulled apart. Discard any old, woody parts. Replant the new sections straight away (see Planting, above), with the growth buds A bud is a small, undeveloped shoot that contains the potential for new growth. Buds are typically found on stems, where they can be apical (found at the tip) or axillary (found between leaf axils) and may develop into leaves, shoots or flowers. visible at the soil surface.

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