Most people may well remember learning how to grow cress as a child. This is such an easy plant to grow as a micro-green that it is the first option many people will try.
You might remember taking an eggshell, painting a face on it, filling it with damp cotton wool inside, sowing cress seeds on the top and then waiting for the green ‘hair’ to grow. This is a common activity in primary schools or for parents to do with their children.
Cress is a great gateway into home growing – perfect to share with your kids, and amongst the plants that give the very quickest results when sown from seed. It really is remarkably easy to grow cress from seed – either indoors on a sunny windowsill, or even outdoors in your garden.
Even for much more experienced growers, it can still be well worthwhile growing some of this useful crop. You can grow cress, Lepidium sativum, almost anywhere, so could be useful for marginal spaces – so you can make the most of every inch of space available – and it is of course a healthy inclusion for your home grown diet.
Cress is high in vitamin K, and 100g provides over 80% of daily vitamin C requirement, as well as a range of other vitamins and minerals. And with all those benefits, knowing how to grow cress can be incredibly beneficial in the garden, a polytunnel or even on the kitchen windowsill.
The Best Types of Cress To Grow
Before we go into how to grow cress, it’s important to know which varieties of this edible herb are best to grow. Lepidium sativum, the annual plant we commonly refer to as cress, or sometimes garden cress to distinguish it from watercress, and some other plants with cress in their common name, has three main cultivars.
The type most people will be used to growing, and may have grown as a child, is common garden cress. Sometimes this is also referred to as ‘plain leaf’ cress.
You might also consider curled or extra curled cress, which has more curled and slightly more serrated leaves.
The final option is Greek cress, which can be a good option to grow to maturity, as well as using it for sprouted seeds or micro-greens. This variety of garden cress has a more pronounced sweet and slightly nutty flavour, with a mild spicy zing and lingering peppery taste.
As well as growing garden cress, you might also consider growing American land cress, Barbarea verna, also known as upland cress and by a number of other common names. It is known as a substitute for watercress that requires less water and has been used as a leaf vegetable in England since the 17th Century.
There is also the related Barbarea vulgaris, commonly called wintercress, The young leaves of this are also eaten raw, or cooked, and the buds and flowers are also edible.
Watercress is known by the Latin name Nasturtium officinale. This is an aquatic perennial that is grown in or adjacent to running water – but which you may also be able to grow on a small scale hydroponically, in a hydroponic or aquaponic growing system. However, it is more challenging to grow than the options above.
How Long Does Cress Take To Grow?
Garden cress can be harvested just a week or so after sowing from seed, as a micro-green. Its little leaves and stems can be snipped off with a pair of scissors. Typically, 1-2 weeks after sowing, the edible shoots are first harvested when they are around 5-12cm tall.
However, you can also leave the plants to grow and mature longer, for true leaves to form. And can harvest once the plants are around 15-17cm tall and begin to form flowers.
How To Sow Cress Seeds
Cress seeds can be sown in a range of locations and will germinate quickly and easily whatever substrate they are sown onto. Sprinkle the cress seeds over the surface of damp tissue, or any other moist substrate, or over potting mix or garden soil, and they should germinate within 24 hours or so.
You can sow cress seeds indoors at any time of the year – even in the middle of winter. Outside, cress seeds are typically sown in early spring and then successionally through to early summer. Since they are hardy, they can typically be sown early – even before the last frosts in your area. You can then sow more every couple of weeks for a continuous harvest over a long period of time.
How To Grow Cress Indoors
First of all, when it comes to how to grow cress indoors, you need to choose your containers, and the substrate onto which you will sow your seeds. Almost any container will do, including reclaimed food packaging, or even eggshells, as mentioned early on in this article.
And you can sow cress only paper towel, tissue paper, damp cotton rag, cotton wool etc… or choose a peat-free seed starting potting mix if you prefer. Growing on paper or another similar medium will be just fine if you plan to harvest early as small sprouts or shoots. But if you plan on growing cress a little larger, soil or a potting mix will deliver more nutrients.
Cress can also be sown alongside other leafy salad crops, herbs etc. in a window box or other mixed planter.
Make sure that whichever medium you have chosen is damp but not soaked. Then simply sow the seeds on top, pressing them down gently to make sure they are in good contact with the damp growing medium or substrate below.
Place the cress into a relatively bright spot and make sure that the substrate or medium remains moist as the seeds germinate and the seedlings grow.
How To Grow Cress Outdoors
On the other hand, if you want to know how to grow cress outdoors, then it should be sown into a prepared bed or border area, where it is relatively cool and lightly shaded. Don’t grow cress in too sunny and hot a spot or it can quickly start to taste bitter and be far less appealing to eat.
When sowing outdoors you an either broadcast the seed to serve as a groundcover plant around other crops, or to intercrop cress in rows between row planted crops in your spring garden. Lightly cover the seeds with a thin layer of soil or compost, the thin them out leaving the strongest plants with a spacing of a couple of centimetres or so.
I like to sow cress between rows of carrots and radishes. I sow a row of cress, then a row of carrot and radish seeds together, then another row of cress, and so on. The radishes and cress help to quickly mark out the rows, making weeding easier. And the radishes and harvested before the carrots need the space.
(Another interesting thing to know when growing cress is that Barbarea ssp. (land cress, upland cress) if you choose to grow these, are known to be useful as a trap crop for certain caterpillars when intercropped with brassica crops like broccoli, cauliflower, cabbage etc…)
When To Harvest Cress
Garden cress can be harvested, seeds and all, while still very small. And with this quick growing crop, you will typically find that they mostly taste best within a few weeks of planting. So it is better to harvest little and often while the plants are young.
This is a cut and come again crop. Using scissors, you can cut off the stems and leaves, and new growth will emerge. Typically, you can obtain a few harvests – 3 and perhaps as many as 5 – from the same sowing.
As mentioned above, however, you can also leave some types to grow a little larger, and harvest handfuls rather than a couple of small snips of leafy greens if you grow in soil or growing medium indoors or in your garden.
What To Do With Cress
Garden cress is especially delicious in sandwiches, or in salads, and it best used raw as it does not stand up all that well to cooking. It can also be used as a garnish, or in a range of other recipes with raw or lightly cooked ingredients. It pairs well with its mustard relatives, and other leaves with a little peppery heat, as well as with milder leaves from your garden, and is also great with egg sandwiches, egg salad, or other egg dishes.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.
To get in touch, visit https://ewspconsultancy.com.