Choose the right time to sow

It doesn’t matter what you grow your seeds in, often the biggest challenge is knowing when to plant them outside.
It doesn’t matter what you grow your seeds in, often the biggest challenge is knowing when to plant them outside.

With a great number of first-time gardeners growing their own vegetables, a question that I am often asked is when is the best time to plant various crops?

This is a difficult question to answer because conditions vary greatly throughout the country.

To make matters more complicated, growing conditions can be different just a kilometre away, caused by what we call microclimates.

These can be created by the terrain or by established trees making a sheltered hot spot and gardeners can be planting out a month or more before it is safe for another gardener, just down the road, to do so.

When you buy packets of seeds, the packet will show the average best sowing times for various regions. This information is general and unless you know your own growing conditions, succession sowings should be made about two to four weeks apart.

If the early plantings fail through weather conditions, your later ones will be more successful, as the weather settles. During the years you will become a better judge of when to sow and plant out.

A gardening diary giving weather conditions each week and sowing times will make a great reference for future plantings.

Keen gardeners like to beat nature and grow plants out of the normal season so they can have early crops, and this can be done in a glasshouse, or by using plastic film over wire hoops to warm the garden soil and protect the germinated seedlings from adverse conditions.

Early plantings can also be helped by placing plastic bottles, with bottom cut off and cap removed, over the individual plants.

The most important aspect is when not to plant out vegetable seedlings.

Late plantings of vegetables, towards the end of autumn, means they have only a small window of growth. In mid-winter, immature crops will just sit waiting for better times. As the daylight hours extend and the soil warms, they get a growth spurt, but because of the previous conditions the plants feel their lives have been threatened and will grow on a bit and then go to seed (bolt) - the crop is a failure, a waste of time and money.

Crops of winter vegetables are planted in summer to grow to near maturity as winter sets in. They will be ready for use in winter and hold nicely over the cold winter months.

For instance, leek seedlings will be planted out in December through to February for succession, winter harvesting. Brassicas, such as winter cabbage and brussel sprouts, will be planted out later in January through till March, dependant on varieties (maturity times) and succession requirements.

The worst problem with brassicas grown for winter is the young plants have to face the problem of white butterfly caterpillars when the pests are most active.

Stress on vegetables that are not grown for their fruit (cabbages as opposed to tomatoes) can make them go to seed prematurely. This can happen by buying seedlings in punnets that have become root bound and possibly have suffered stress through inadequate watering.

Always look for the very young fresh seedlings of non-fruiting plants to buy, even if you need to grow them on in their punnets till they are of a nice size to plant out.

Bolting can also occur during the spring when weather conditions fluctuate from nice warm sunny days to cold miserable days. The plant's growth responds to the sunny warm days and then they sulk in the cold windy days. This stress of change, makes the plants believe that conditions are not good and their lives are threatened, so all they want to do is produce babies, and go to seed.

A number of gardeners like to do late plantings if they live in areas not prone to early frosts.

Late plantings of sweet corn in January can often result in a second harvest of cobs before winter sets in.

Tomatoes sown from seed in December and January should give you more ripe fruit after your earlier plantings have finished.

It is still not too late to plant seeds of summer crops unless you live in an area prone to early frosts.

Keep the soil moist at all times using non-chlorinated water.

If you do not have room for a vegetable plot, use containers or planter boxes to grow as many vegetables as possible. Fill the containers with a good bought compost, not potting mix.

Problems? Phone me on 0800 466 464 or email

The Southland Times