When thoughts turn to tomatoes

01:30, Aug 26 2014

Now that we are into August, it's the right time to start thinking about tomatoes for the new season.

The traditional time for planting tomatoes outdoors in many parts of New Zealand is around Labour Weekend, which is about 10 weekends away.

That does not mean that you have to wait until then to buy a few plants for the garden.

Tomato plants planted out in Labour Weekend are unlikely to produce ripe fruit till early in the new year except for a few quick- maturing types such as the Sweet One Hundreds.

On the other hand, if you were to start now with seeds you are likely to have plants with fruit on by Labour Weekend and have ripe tomatoes before Christmas.

Garden centres are likely to have a few varieties of tomato plants available now, including the first of the grafted tomatoes and that puts you even further ahead for possible ripe fruit by, say, about November.


Gardeners who are fortunate in having a glasshouse can sow some seeds and buy a couple of plants for growing on.

For those that do not have a glasshouse there is no reason that you cannot get an early start as well, it just takes a little more care.

Let us look at how to go about this without a glasshouse, but it applies similarly to glasshouse owners.

Buy a packet of tomato seeds from your garden centre. The first thing to do is germinate a few seeds and this can be done in an old punnet.

Fill the punnet with a good potting mix to about two-thirds full then place six seeds nicely apart or one seed per cell on top of the mix.

Spray the seeds with a solution of Magic Botanic Liquid (MBL) at 20ml per litre of non-chlorinated water, so the seeds and the mix are nicely wet.

Cover the seeds lightly with either a little more mix; alternatively, use sand or fine pumus.

Spray the surface to moisten. The seedling tray can now be placed onto a heat pad if you have one, or in a warm room for germination. Spray the surface every day to keep it moist.

Once a show of foliage appears, the seedling tray needs to be moved to a spot outside that is sunny but sheltered from frosts.

The easy way to do this is to take an old drawer and place the tray inside it with a sheet of glass over the top to cover. If it looks like there may be a frost, place a sheet of cardboard over the glass with some stones to hold it in place, or place the cardboard under the glass for the night. Remember to remove the cardboard in the morning.

Other punnets of vegetable seedlings can also be placed inside the drawer for early plantings.

Mist the young plants every day or two to keep the mix moist. Do not over-water.

When the plants have established their true leaves (the first leaves are the embryo leaves from germination), you can wet down the tray and carefully lift the young plants out without disturbing and damaging the roots.

They are now ready to go into their first small pot, which should be no wider than about 50mm and up to 70mm tall. Use a good compost as the new growing medium. If your drawer is deep enough the small pots can be placed back inside with the glass to cover. If there is not sufficient height then place the pots in a sunny spot and protect from frost.

You may want to move them indoors or onto a covered porch or into a shed overnight when it looks like a frost. They should also be protected against cold wind and rain during the day.

The secret is to keep the mix just a little moist - and certainly not wet - as it will make it colder for the plants.

When the plants get up to about 100mm tall in their pots, it is about time to repot them into a 120mm pot using compost again. When you transplant them this time, you will bury the plants deeper, up to about their first set of leaves. This then allows the plant to root up the mix- covered trunk, increasing the amount of roots to nourish the young plants. Apply a little more tomato food and spray the plants every couple of weeks with MBL. This last step would apply also to purchased tomatoes in punnets, cell trays or grafted tomatoes, which come in a smaller pot.

With grafted tomatoes, never plant deeper than the graft union, which should be above soil level.

When your plants reach about 200mm tall then repot them into 200 to 250mm pot.

At this time you will probably have the first trusses of flowers and the beginning of fruit set.

Allow the plant to grow to about 500mm tall and then if conditions are favourable, they can be planted outdoors with protection or repotted into a 20-litre container for dwarf- type plants or into a 50-litre or larger container for tall-growing types as their final home.

When repotting, wet the mix down first and transplant without disturbing the root system by tapping the edge of the pot on a bench to remove while supporting the plant with your other hand.

Apply more tomato food with Neem Granules at each transplant time.

A monthly spray of Perkfection will assist in preventing diseases.

When removing laterals or any leaves, spray the wound immediately with a solution of Liquid Copper to prevent disease entering the plant.

Let's hopefully look to a good season and lots of fresh home-grown tomatoes - they certainly taste far better than bought ones.

Problems? Phone me on 0800 466 464 or email wallyjr@gardenews.co.nz

The Southland Times