The tomatillo, pronounced toh-mah-tee-yo apparently, was domesticated by the Aztecs, perhaps as far back as 800 BC. Tomatillos are in the solanaceae family and are related to tomatoes and Cape Gooseberries. The fruits themselves are small (golf ball sized), spherical green or green-purple in colour depending on the variety, and are covered with a slightly sticky, waxy layer which is very effective at reducing moisture loss.
The fruits are further protected with a green surrounding papery husk, formed from the calyx, which turns beige when ripe.
The fruits have a curious tart flavour with a hint of green tomato and pineapple, and are used extensively in Mexican cooking for green sauce or salsa verde. The fruits are high in ascorbic acid and much higher than tomatoes in solid matter(9%). There is no free juice in the tomatillo fruit.
In the UK, especially the North, it would be best to grow them in a greenhouse, just like tomatoes as they like warmer temperatures than are readily available outdoors. They will easily grow to 2 m high in a season and carry a copious crop of fruit in good conditions. While they are indeterminate, it is probably better to let them grow without pinching out, provided you have enough space. As they are floppy, try keeping them in check by tying twine round the whole plant at intervals and provide support.
They are extremely floriferous but there are many reports of problems getting them to fruit unless you have at least two plants, the temperature is high enough, and there is ready access for insects, especially hover flies which go wild for them. Hand pollination with a brush or finger does not seem to work. Tomatillos are self-incompatible and all plants are hybrids.
Sow the seeds in pots in a warm place(18 C) in March or April, in the same way and time as you sow tomatoes. Once germinated, continue growing at lower temperatures to prevent them growing leggy, until it is warm enough in late April or May to plant them out in their final position in the greenhouse. If growing them outside in a warm mild district, plant out after all danger of frost is over as they are very frost tender.
Warning. On no account plant out these sub-tropical plants before the last expected date for frost in your area. This could be mid May for the mildest areas such as Southern coastal areas, and early June in the North of the UK. Even then, provide cloche or fleece protection for the first few weeks as cold nights and winds will cause plant damage. Gardeners are regularly caught out by late frosts occurring during the traditional cold period known as “The Ice Saints”, usually just before mid May. Remember, one night of a late frost will kill your sub-tropical plants!!
Feed them with tomato fertilizer and keep them well watered.
Pests and diseases do not seem to be much of a problem in the UK.
Harvest the tomatillos in late Autumn when the fruit has swollen to almost fill the surrounding papery husk, which should have changed colour from green to beige. Leave the papery husks intact as added protection to the fruits. Remove any remaining fruits when the plant starts to die down, and place in a sunny windowsill.
Storage of tomatillos. Due to the protection of the sticky, waxy coating to the fruit itself and the surrounding papery husk, tomatillos will store in perfect condition for at least 5 months on a windowsill.
Cook tomatillos to make Mexican style “salsa verde” or add to “fry ups” as a piquant taste instead of tomatoes, or make chutneys or pasta sauces. Can also be eaten raw in salads.
Suggested varieties of tomatillos
Purple de Milpa Physalis Ixocarpa. Heirloom variety with blush and purple fruits, when ripe.
Tomatillo Verde. This is the traditional variety used in Mexican dishes, and picked while the fruits are still green.
Dr Wyche’s Yellow Tomatillo Physalis philadelphica. Produces medium sized fruits with yellow skin overlaid with a purple blush.