Tomatoes in a TIGHT SPACE

Embrace the tomato-planting season, says PHIL DUDMAN, with compact, heavy-cropping varieties perfect for pots

One good reason for growing tomatoes in pots is a lack of space. If you don’t have a garden, or have run out of room, you can line up some pots on a sunny balcony, deck or courtyard and get growing. And if your soil is poor or you’ve had problems with nematodes or soil-borne diseases such as wilts, then growing tomatoes in pots filled with fresh, disease-free mix is an excellent option.

Container growing is different from growing tomatoes in the ground. There are a few things that you need to get right, and when you do, you will enjoy bumper returns for your efforts.

Suitable varieties

Tomatoes can be divided into two basic types – determinate (‘bush’) and indeterminate (‘vining’). Indeterminate types grow like crazy and need lots of pruning and a frame for the vigorous vines. Determinate varieties are more compact and require minimal staking and virtually no pruning, so work best in containers. Look for varieties labelled as patio tomatoes, which include bushy heirlooms and modern hybrids bred to be remarkably compact and productive.

While vine varieties flower and fruit continuously over the growing season, the entire crop in most determinate types ripens over a few weeks, then vines die. There are exceptions, such as the stout, semi-determinate hybrid Cherry Falls, which produces over a longer period (see Marketplace on p10). This glut is good if you’re into bottling, but if not, stagger the planting or grow a range of varieties that mature at different times.

Choosing a pot

The more root space the plants have, the better they perform. Pint-sized hybrids such as Florida Basket grow to just 20cm tall and produce well in a 35cm tub, but larger bush types such as Green Grape need a container that is at least 50cm wide and deep. Lightweight plastic containers are best, and choose a pale colour that reflects the heat. Terracotta and ceramic pots should be sealed on the inside, so they don’t dry out too quickly.

Boost potting mix

A good-quality potting mix does the trick, but a few additives make it better. Combine equal parts of potting mix, compost and coir peat that has been soaked in a solution of liquid kelp and fish emulsion. This mix holds moisture and nutrients, but drains well. Don’t re-use it to grow more tomatoes.

Training plants

One or two short, thick stakes will support smaller bushes. Larger types benefit from longer, heavier stakes or you can use a sturdy cylinder made of wire mesh. There’s no need to pinch out the shoots on determinate types – let them develop their natural bush form. Each stem will bear plenty of fruit.

Water & feeding

Tomatoes need more watering in pots than they do in the ground. Don’t let them dry out as this leads to problems such as fruit split and blossom end rot. Check and water pots daily, if needed, and consider setting up an automated dripper system if regular watering is difficult to manage.

Empty saucers after watering to avoid root rot. Cover the surface with straw mulch to preserve moisture and keep roots cool. Add a balanced organic fertiliser after planting and give them a follow-up feed every six weeks. Supplement this with weekly applications of diluted liquid seaweed and fish emulsion.