Although they are best suited to mild or cold climates they are pretty adaptable and will grow in much warmer climates even in the subtropics. Frost is no problem as the ferny plants die off each winter.
They like deep crumbly soil so that it is easy for the spears to push up. A PH level of about seven or higher. Plant them in full sun where you want them to permanently stay. protect from strong winds. They are not suited to heavy clay soil.
Seriously Weird Looking
They produce new shoots (or spears) each spring – this is what you eat. They don’t get edible spears for two seasons so you need to show a bit of patience if you plant them from seed. It’s better to plant two year old “crowns”. The spears appear before any of the green ferny stuff so they can look seriously weird when they poke up through the soil.
Male and Female
There are male and female asparagus plants – the male ones produce better spears. You know if you have female one if it gets red berries in the second season – pull it out as the berries growing into plants can be a nightmare for the environment – the birds eat the berries and off it goes.
You should be able to buy a two year old crown from the nursery or plant supplier.
Dig the soil to at least a spade depth add organic matter and a bit of general purpose fertiliser.
Plant the crown about 6 – 8inches (15-20cm) deep and about 12 – 20 inches (30 to 50cm apart) and cover with about 2 inches of soil as the spears grow cover with more soil until the ground is level.
Water regularly and give regular high nitrogen fertiliser in summer to encourage the green ferny top growth. Cut down the dry yellow fern to the ground in winter and give another dose of fertilizer to encourage spears in spring.
I have included a video below to show you what they look like and how to plant them. This isn’t me I got this from YouTube I couldn’t have done it better myself – Enjoy!
White or Green Asparagus and when should I pick it
White and green asparagus are the same thing. If you want white asparagus you need to pull the soil up around the plant to about 8 inches to make a hill to stop the light getting to the spears.
Picked it when the spears are about 8 inches (20 cm) long and before the tips open – just cut the green spears off at the ground. When the white ones break the surface stick a long knife into the soil and cut the spear about 8 inches under the soil. After you pick all the spears for the season level the soil out again so that you can mound it up again next year.
Mary Washington is the most common well known variety for home gardeners and is the one I am aware of. I have done a bit of research and found that other varieties which may be more disease resistant are the all male hybrids Jersey Gem and Jersey Knight which produce significantly more yield. Check for availability in your area. if you are in the US Jersey Gem and Jersey Knight can be purchased from Burpee Gardening
Atlas is another variety withfatter spears and which is available from California Asparagus Transplants and Seed, Davis, CA.
In the UK the BBC recommends the following varieties Gijnlim – heavy crops one year after planting, Jersey Giant – dark green spears with a purple head, Jersey Knight Improved – thick, but tender spears, Purple asparagus of Alberga – Italian heritage variety with purple spears, Backlim – thick, green spears
In Australia Garden Express has Mary Washington.
In Canada there is a variety called Viking has been developed which is hardy to zone 4. Jersey Gem and Jersy Knight which were developed in California are apprently only hardy to zone 5. See the planting zone maps here
How Much To Plant
I have read that the recommended number of plants to grow is ten per family member. I don’t know about you but this is too much space to give up in my garden. If you plant the newer hybids you may be able to get away with half that number – check with your supplier.
If you know anything extra about asparagus that you would like to share or if you know of a good supplier that you would like to recommend let us know by adding a comment below.