Outdoors

How to: Vegetable gardening in small spaces

Article by Your Home and Garden

As the price of getting your five-plus a day sky rockets, it pays to know size isn’t everything when it comes to growing your own incredible edibles

On balconies, storeys off the ground, in pocket-sized townhouse courtyards, in narrow strips along suburban drives or slender window ledges, vegetables are being grown. This is a pastime and way of life that can be easy, healthy, fun and so rewarding – and one that proves size isn’t everything.

The number one point to remember is that plants want to grow. They will try to survive even if the odds aren’t good. And it’s up to you in this mutually beneficial relationship to help them as much as you can. Whether they’re in containers or in the ground, vegetables require four primary requisites to grow – soil, water, sun and warmth.

Soil

Most garden soil is adequate for your first crops of easy-to-grow, unfussy vegetables. Just pull out all the weeds, roots and all, and break up big clumps of dirt before sowing or planting seedlings.
While proprietal potting mix is the easiest for pots, incorporating dirt from the garden, or hummus (decomposed leaves and other detritus found under trees) will aid naturally the mix’s water-retaining capacity. Layers of stone at the bottom of containers will stop the soil becoming waterlogged, which most plants hate, should you or the skies be heavy-handed with moisture.

Water

Most vegetables do not like drought or floods, with regular deep watering of the soil preferable to more frequent sprinkling of leaves. Check soil moisture by poking your finger in a couple of centimetres. Generally, the smaller the plant the shallower its roots. As water evaporates from the soil surface, these plants will need more regular watering. A lack of water will cause many vegetables to bolt – they think they are about to die so quickly put out a flower head for seeds to ensure the lineage will continue. Lettuce, coriander and basil are especially prone to bolting.

Sun

Vegetables that cope with more shade in summer include lettuce, spinach and silver beet. Most others like sun for at least six hours a day. Conversely, the summer shade lovers are best grown in a sunnier spot in winter.

Warmth

The golden rule is don’t sow too early, especially outside, else the seeds might fail to germinate. Plant too early and the seedlings will fail to thrive, often never catching up with even those planted weeks later. Depending on your location, don’t plant tomatoes, courgettes and corn till the end of October through to middle of November – when just about all likelihood of frosts is gone. Shelter plants from cold or strong winds.

Space

Asking how much space is needed to grow vegetables is akin to asking how long a piece of string is. You plant according to the space. That said, one silver beet plant will usually require about 25cm square; lettuce a little less, and tomatoes are best about 50cm apart.

Seeds

In the ground or containers, even when space is not an issue, avoid sowing or planting too much at once. Avoid glut and famine scenarios with successive sowings and plantings, two to three weeks apart. That said, excess seedlings can easily be thinned and either eaten, given away or swapped with like-minded friends or neighbours.

Sowing in containers

One advantage of this is getting a head start on the season by starting off seedlings indoors on a sunny window ledge or veranda, but you have to monitor soil moisture closely as trays tend to dry out quickly, and especially so indoors. Another plus is that a greater variety of seeds are available than seedlings. When seeds are about 2cm tall transplant into the garden or a larger pot. If sown into the pot in which they are to grow, thin out (see below).

Sowing direct into the garden

Not all vegetables cope well with transplanting, notably root crops. Others germinate so readily it hardly warrants starting them off in seed trays and transplanting, these include lettuce and silver beet. Most seeds like to be covered with a depth of soil equalling their size, which means the finer the seed, the less soil on top. After covering press down firmly and water well with a fine spray. Generally, seeds are best sown in straight lines so when the seedlings emerge it is easy to distinguish them from weeds. Try as you might it’s often difficult to sow thinly enough to avoid overcrowding. Such seedlings will be spindly as they compete with one another for space, light and nutrients. Thin regularly through their first few weeks when they are a couple of centimetres high. Thinnings may be transplanted or eaten.

Seedlings

Buying seedlings avoids any fluffing around with sowing and caring for seeds. It also avoids ending up with way more seedlings than you can possibly use – a common outcome when growing space is limited. To transplant the seedlings, gently extract them from the container they come in, make a hole in the soil they are to grow in, big enough to hold the roots, place the seedlings roots in the hole, gently back fill with soil, and press down firmly. Water the seedlings well. This is best not done in the full heat of the day.

Growing vegetables in containers

Most vegetables can be grown successfully in containers outside, which have the advantage of being moved to the sunniest, most sheltered spots. As well, the soil is easier to get right – especially if proprietal potting mix is used. A 10-litre container – the size of an average bucket – is about the smallest container suitable. A container this size would generally support one tomato plant or four lettuces or two silver beets, one courgette or 25 carrots or radishes. Try attaching pots to fences or other vertical surfaces to greatly increase your production area.

Easy vegetables to grow

Corn Plant in blocks rather than rows so they support each other.
Courgettes Smaller varieties are available of these large spreading plants, which are good for containers.
Lettuce and coriander Grow these somewhere sheltered from the heat of the midday summer sun.

Radish and carrots Roots crops do best in light, sandy and friable soil. They can grow malformed in heavy soils. Ball-shaped varieties are best in heavy soil.
Silver beet and cavolo nero These will grow pretty much all year round in most of New Zealand.
Tomatoes Plant deeply, burying some of the stem to give them greater stability. Place stakes when planting. Nip out small stems growing in the elbow between the stalk and branches to encourage one main trunk and side fruit-bearing branches.