Growing Tips


See tips on soil preparation for conditioning soil prior to planting.

Once established in the soil, plants should be allowed to grow for a couple of weeks before the first fertiliser application. Nitrogen is good for initial growth, but if used too strongly, will deny plant of good fruit set. A fertiliser higher in potassium encourages fruiting. On the packet of fertiliser should be the NPK ratio. N (nitrogen) should be lower than K (potassium). Don’t worry about the P (phosphorous), because most Australian gardens have good levels of this, so manufacturers won’t add too much of it. You might choose to dig in a fertiliser, but I find mixing up a liquid fertiliser much easier.

Some growers have put baby powdered milk in the watering can to add calcium to plants. Plants lacking in calcium (often due to inadequate watering or too much nitrogen) are susceptible to getting blossom end rot. Many of the liquid tomato foods (like Phostragen) contain added calcium

Over the life of the plant it should be fed at least 2 or 3 times to ensure adequate growth and development. Plants in pots may need to be fed more often. Look at the leaves of the plant. If they are yellowing or fading, or if the tips are black or purple, then the plants are hungry. They have that hard look. They are lacking in nutrients and will gradually become wekaer. An overfed plant is very lush green and soft – this plant would be susceptible to wind and insect damage.


The key with watering is regular intervals. For example watering 2 days in row, missing a week, then watering 3 times in a day, is not the way. Tomato plants require frequent watering to establish good growth and fruit set. Stress due to lack of water will reduce the quality and yield, and ultimately shorten the life of the plant.
In mild conditions, if rain has not been regular, or dry conditions prevail, a deep watering of 40-50mm every week will sustain the plants and encourage good root growth. In warmer weather, this may be needed every 2 or 3 days.

Think about your soil. If it is a clay soil, you will not need to water as much as a garden with a sandy soil. Stick your finger in the soil. If it is damp, do not water. If there is no moisture at all, then water.

For pots, remember, deep saucers are extremely handy, particularly if you go away for a few days. They also save water. The trick is to let the plant use all the water, rather than continually topping them up, which can give the plants ‘wet feet’ (lack of oxygen to roots, often resulting in poor growth).

Don’t wet the leaves in the late afternoon, as wet leaves during the cold of night can cause fungal or bacterial problems. Many people just water around the base. As the plant is fruiting, If you don’t water for over a week and then we get heavy rain, the sudden surplus of water can cause fruit to split.


Staking should be done early, to prevent damaging the roots. Also, if you miss that first tying up of the plant, it tends to droop down and get a kink in it, which it never seems to grow out of and you lose that nice straight stem that you started off with.
The reason we stake plants, is that once they start to fruit, there is so much weight in the plant, that if the plants have to stretch and strain by supporting themselves, they will stop fruiting any more. The plant is physically stressed, and it could easily split in the stems, causing an infection point for a secondary problem.

You can use 1 stake per plant, but some people prefer one on each side. Use other things as stakes – the fence, wire, or even an old bed frame! Anything that will provide support to the plant, although watch out with metal that can heat up in the sun and burn tomato leaves.

Tie the plant with material that has some ‘give’ in it. String will quickly cut into a stem on a windy day. Stockings, plant-tie ribbon or even rubber ties are good.

Remember there is a non-staking bush roma called San Marzano, and a non-staking bush cherry called Tumbler

Think about how you will prune the plant, as to what your staking requirements will be.

Pinching or pruning

To prune or not to prune – that is the often hotly debated question. I know Clive Blazey of Diggers Seeds is absolutely against pruning any tomato plant and has figures to prove it reduces yield. Commercial growers on the other hand are fanatical about pruning and the number of trusses of fruit a plant produces. I am a bit middle of the road and tend to take out the first few shoots, then let the plant do its own thing. This seems to improve airflow through the plant and keeps the bottom of the plant clean. If you prune really hard, sometimes in long hot summers, the fruit can be scalded. Do think about how you are going to grow and stake the plant. If you wanted to grow a tall plant up a pergola pole, you may only want the one main leader. The less leaders, the slightly bigger your fruit may get.

The sideshoot or sucker are new growths between the stem and the shade leaf. Don’t remove the shade leaves, as they protect the plant. Pinch the sideshoot out if it is only a couple of cms in size. If it is bigger, cut it off with a scalpel type knife so as not too open up a messy wound which could become a disease entry point.

The main leader is at the top of the plant. The second strongest leader is the next one, below the first flower truss. These are the 2 that the commercial growers develop. They may then (depending on variety) pinch out further branching until two more flower trusses form, then branch again.

A determinate doesn’t need any pinching – ever. It usually includes the shorter growing varieties and its growth structure is already determined. Nothing we do will change that. It is the taller growing indeterminite types that can be influenced in how they grow, by the way we pinch them out, or not pinch them at all.


Tomatoes have the highest yield of any vegetable. Do remember that selecting different varieties to grow, will extend your harvest season. In cooler climates, an early fruiting variety can also be planted late in the season for a late autumn harvest. Sometimes however you may harvest a lot of fruit in a very short time. Make the most of your prescious harvest – sauces, freezing or drying are easy !

Birds, possums and rats can be a problem at harvest time. If you find you are losing a lot of fruit, pick fruit a bit earlier, and ripen on the window sill. Possums and rats tend to come back and eat from the same piece of fruit, so I sometimes leave it there. If however a blackbird gets the taste for your tomatoes, he or she will persistantly come back until all the fruit is gone. Sounds and bright reflective colours blowing in the wind will scare birds away, but only for about 2 weeks. These things include wine cask inners, video tape, and there is a noisy little windmill made from 2 aluminium cans. I have even seen fake eagles and owls being used to scare birds away. Netting and even a cage made of chicken wire have also been used.

If you leave fruit on the bush and don’t water enough, heavy rain can cause the fruit to split.


  1. Lisa says:

    My tomatoes (roma, tom thumbs) all look poorly. Curling leaves with black spots???? Please help last year I had huge sucess.

  2. sandy says:

    what is the best treatment for white fly infestation?

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