The Ultimate Guide to Homegrown Asparagus in South Africa

Delightfully tempting, the idea of growing your own fresh, tender, yet frost-hardy asparagus in your own home food patch sounds good. There are only a few things you’ll need to get right for you to enjoy your own homegrown asparagus. Let’s get started…

Good things take time

Firstly, you’re going to need a lot of patience! Asparagus is not grown in a day, or even a year. However, the wait will be oh-so-worthwhile. For your first harvestable, properly edible crop you’ll have to wait until the 3rd or even 4th year of growing. Just keep tending them and remember that once they’re properly established, each crown (an underground rhizome) will yield up to 25 spears per season – and will keep going for up to 25 years! Leave them to grow strongly in their ‘infancy’, as the more time you give them to establish, the longer and heavier they will bear.

Planting time and position

Spring or autumn are the best times to plant asparagus crowns out, so if you’re planning on planting come late winter once the frosts have finished or early September, get cracking on getting your soil ready now!

Asparagus needs a full sun situation where it will receive 6-8 hours of sunlight a day. Morning sun is preferred as this will encourage a more robust, compact plant, and will help the plant fight any ‘illnesses’. Due to the plants being so long growing, you’ll need a permanent spot in the garden for them, one which can accommodate a plant that can get quite wide and tall.

The best soil for growing asparagus crowns 

 Your soil will need to be well-draining, as the crowns will rot and the roots will get destroyed if they’re in standing water. If you have clay-ey soil there are ways around it. You can consider growing in raised beds, or trenching really well. You can also grow in containers, but make sure that it’s a deep pot, as asparagus has a very deep root system (sometimes reaching down to 3m in the ground). 

You should use good quality potting soil and ensure that the pot drains properly. Our local veggie growing guru, Linda Galvad suggests using a potting mix in the following ratios: 

• 2 x vermiculite
• 2 x organic potting mix
• 2 x organic compost
• 1 x vermicast

 You can do the same in your trench/bed too. Adding loads of organic material, like compost, to any type of soil before you plant out your crowns is best practice – as with planting out anything. If you have acidic soil, you can add lime to the soil a month before planting, as asparagus prefers a more alkaline growing medium.

There are some who suggest soaking your crowns in a compost tea for 20 minutes to ensure they’re hydrated, which apparently helps them to establish faster. It won’t do any damage if you do!

Once your soil is in tip-top condition, make sure you’ve removed all perennial weeds. Then plant the crowns 20 – 40cm apart, about 5cm below the surface of the soil. Cover with a good layer of compost to keep the crowns warm, weed growth suppressed, and evaporation down. After a couple of weeks, you can add a little more soil until it’s slightly mounded above the ground to allow for settling.

Watering and feeding 

Make sure you water often in the first two months after planting out, while the plants are sending down roots, and in the absence of rain, water deeply at least every 2 weeks. Apply a top-dressing of liquid or balanced fertiliser in spring and autumn.

Companion planting 

Don’t grow your asparagus crowns alongside garlic, onions or root vegetables – they’re not good bedfellows. You should rather plant any of the following nightshade plants, herbs or flowers alongside asparagus:

• Tomatoes and eggplants
• Coriander, basil and parsley
• Marigolds and nasturtium 

Male plants produce better 

Bear in mind that male plants produce better than females, which spend a lot of energy producing seeds. However, it’s not possible at an early age to determine whether your plants are male or female, but you will get crops from both. Sourcing your asparagus crowns from a reputable supplier should provide you with pre-selected males only.

As summer progresses, watch out for red fruits on the ferns, which is an indication of it being a female plant. Let it grow for the season, making sure you’ve marked where she is, and if you are strapped for space and would only like male plants, dig her up in the next spring, taking care to remove all the roots.

Further care

Asparagus shoots will grow in spring, but remember – no harvesting in the first few years. You’ll only harvest shoots which are bigger than 1 – 2 cm when they’re older, leaving the rest to grow into leafy ‘ferns’ which can in some cases reach up to about 3m in height – the shoots that will ensure that food will be created for the production of next year’s crop. If there’s frost forecast, protect the tender leaves with a covering of frost-guard or straw. Leave the ferns to die down in autumn, trim off the dead stalks, and pile on compost!

Whatever you do, don’t dig them up to see what’s happening if you haven’t seen any shoots yet. They can sometimes take two or three months to wake up, and they don’t like being disturbed.

Happy growing!