Saturday, 23 May 2009

Feeding Tomatoes

Tomato Plants are heavy feeders when they are fruiting but will only require the minerals and nutrients that will already be found in new compost/soil.

This means that feeding tomatoes is unnecessary until the flowers set and small, pea size fruit appear.

An easy mistake to make, if you are new to growing tomatoes, is to give your small plants tomato food. This food is only for tomato plants when they are fruiting and may cause root damage.

If you want to give plants a boost before they begin to fruit I would recommend the following:

  • General purpose plant food such as miracle grow at half strength.
  • Liquid seaweed extract - a general tonic and very useful when transplanting.

There are other nutrients that may be given such as epsom salts (magnesium sulphate) and extra calcium (to help prevent blossom end rot). However, these should be given with care because sometimes too much of one mineral may prevent a plant absorbing another, especially if foliar feeding.

The thing is not to get too obsessed with feeding tomato plants (as I have done in the past) because if you do, you'll probably give them too much.


If plants have been transplanted into new compost or soil - within the last five weeks - they do not need to be fed.

When transplanting, a half strength feed with general purpose food is helpful (but not essential) because it helps the plants become established in their new home.

Give tomato food (only) when plants start to fruit - little and often is the best way. Professional growers usually feed at every watering, at a reduced strength, so plants alway have access to food.

Monday, 18 May 2009

Prevention Is Better Than Cure

This season I'm determined not to get caught-out.

I've suffered blight, disease and blossom end rot in previous seasons but I think this time I am well prepared.

All of my outdoor plants are under some kind of shelter to avoid blight due to rain.

I've sterilized all the equipment used last season to help avoid disease and used fresh compost.

Blossom end rot doesn't usually effect cherry tomatoes but all the medium and large varieties have water retaining gel added to the compost to prevent is from drying out and causing calcium deficiency. You don't need gel if you can keep the soil constantly moist - but that can be difficult.

Another tip I should mention is to stake and support your bush varieties. Windy conditions can put a lot of stress on main stems and can cause damage. For low plants like Tumbling Tom, stick a few short canes into the compost between the branches.

Saturday, 16 May 2009

Yellow Leaves

If the leaves at the bottom of your plants are showing signs of turning yellow, don't worry!

All the goodness from the roots goes into producing top growth and the lowest leaves are often ignored. If the higher leaves of your plants are turning yellow it is probably because they are struggling to absorb nitrogen.

In this case, a foliar feed with a balanced food like miracle grow will help. Deficiencies are often due to low temperatures are plants that have used up all the food in the pot they are in, in which case move to a bigger pot with more compost.

I usually remove yellow and poorly looking leaves from the bottom of tomato plants.

Tuesday, 12 May 2009

So Far ... So Good!

I've gone to the effort this season to make sure that all of my outdoor plants are under cover with a lean-to placed here and there around the garden.

Last season was so disappointing because of blight, that I decided that if I were to continue to grow outdoors then It was necessary to keep the plants out of the rain. It only takes a few wet days and a few cold nights to spoil things.

Red Alert has shown just how good a variety it is, by producing the first tiny pea-sized fruit of this season. I sowed the Red Alert seed after Tumbling Tom back in February but it caught-up and over-took Tumbling Tom which I sowed two weeks earlier.

However, they are both fantastic varieties and earliness is not the only reason for choosing a which variety to grow.

There are a few mistakes that are very easy to make that can put all your hard work in jeopardy. I like to be positive and have a glass that is half full and not half empty, but the following are things I would try not to do.


Give your plants too much water (many people kill their plants with kindness).

Feed your plants with tomato food until they begin to fruit.

Pour water over the leaves (tomato plant leaves like dry conditions).

Use compost and old soil from last season - it probably contains diseases and bugs.

Feel the leaves from plant to plant - you may be spreading diseases on your fingers.

For more tips about growing tomatoes please visit

I'm always happy to answer tomato related questions if I can.
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Friday, 8 May 2009

Tomato Root Space

How much root space a tomato plant needs depends on the variety and the size of fruit it produces.

Bush Varieties

Tumbling Tom and Balconi Red are quite happy in a smaller area than Red Alert - all of which produce cherry tomatoes.

Oregon Spring, Siberian, Alaskan Fancy and New Yorker (these are medium and large fruited) will all require more root space than the cherry varieties or they will run out of energy before the tomatoes fully mature. They are also bigger plants.

So how much root space, or size of container should they be planted in?

There are two things to consider:
  1. Size of Plant
  2. Size of Fruit
Red Alert is a larger plant than Tumbling Tom even though the fruit are about the same size.
Larger plant = larger root system.

When dealing with plants that are about the same size but produce different size fruit, the larger fruiting variety requires more root space.
Larger Fruit = larger root area required to bring larger fruit to maturity.

Answer: A Tumbling Tom (small cherry plant) will be quite happy in a 5 Litre pot - around 9 inches diameter.

An Oregon Spring needs a 10 Litre container (at least) to perform to its full potential because both the plant and the tomatoes are large.

Tall Varieties (Also known as Cordon and Indeterminate).

The issue here is:
  1. The size of fruit
  2. The amount of trusses you intend to grow.
These plants are usually grown in grow bags so the question is - how many plants in a grow bag?

Answer: two medium or large size varieties, or, three medium to cherry size varieties in each grow bag. Most average size grow bags contain around 35 litres of soil/compost.

With regard to the amount of trusses ... you could grow two plants with six trusses each or three plants with four trusses each - you still end up with the same amount of trusses!
Usually it is four trusses outdoors and six trusses in the greenhouse.

Few! ... if you are still with me and haven't decided never to visit my blog again, well done!

Thursday, 7 May 2009

How Much Room For Roots?

As we get to the time of the season when we plant our well cared for plants into pots and containers - as well as grow bags of course - my temptation is to over-crowd with too many plants.

For example, I always sow more seeds than I should (just in case) and end up with far too many plants and not enough containers and compost to go in them. Faced with the dilemma - should I give my extras away or put two in a large pot instead of one!

Experience tells me to not over-crowd but I sure would like to keep them and plant them now!

Well, this season I'm trying to be good and give each plant the root room it should have for the best results.

What is the best amount of space or soil amount for each variety? I'll let you know in my next post coming soon!

Wednesday, 6 May 2009

The Wind - Support Your Bush Varieties Too!

I'm not going to get caught-out this season like I did last year when almost all of my outdoor plants got tomato blight. So every plant will get some kind of cover from the rain as I've constructed Lean-to's and all sorts of protection around the garden.

The problem is, as soon as you have sheets of polythene and other plastic covering, the wind becomes an issue. Chasing covers into the next door neighbors garden is a bit embarrassing!

The other issue with windy conditions is the direct effect on your plants and the damage it can cause to the base of the main stems. Although bush varieties are often thought to grow without support, I usually stick a cane or two around each plant to help when it's windy and also when it is heavy with fruit.

Bush varieties like Red Alert are taller than Tumbling Tom for example and will need some support. Sometimes a branch will become so heavy with fruit that its weight will pull from the main stem so tying branches to some kind of support can be helpful.

However, do remember to be careful with the ends of canes ... eyes can be vulnerable so it's a good idea to make the tips easy to see.

Monday, 4 May 2009

Tomato Plants

There's still time to grow tomatoes this season if you buy small plants from the garden center.

Look for those that have dark green, healthy looking leaves and stems that are not "leggy" - that is thinner and taller than they should be ... compare them to the other plants of the same shelf.

Of course you probably won't get the selection of varieties that are available from seed, but buying small tomato plants is a great way to get started at this time of the season.

Remember ... keep those leaves dry!

Sunday, 3 May 2009

Grow Bags for Tomato Plants

This post is about making the most of your grow bag or, "grow bag optimisation" to put it in a rather grand way!

Perhaps the biggest drawback with grow bags is that they can dry out quickly, especially when plants are fruiting. So here are a few suggestions to help keep the moisture in.

Make slits in the top of the grow bag and plant so that the plastic can be replaced around the bottom of the plant and the compost is not exposed and moisture is unable to evaporate.

Sink pots directly into the grow bag so that the plant roots can grow out of the bottom of the pot and into the grow bag (see above).

Add a few handfuls of perlite to the soil to aid water retention. Also, water retaining gel is a good option.

You will need to pierce drainage holes but make them at the ends of the bags rather than at the sides to help keep the entire compost area moist.

To help watering, sink a large pot in the middle which can be filled easily and the water can make its way out of the bottom of the pot (see pic. black pot between two Sungold plants).

Saturday, 2 May 2009

Foliar Feeding Tomatoes

The quickest way to get nutrients into a plant is to spray the leaves with a suitable plant food.

This may not necessarily be tomato feed as there are other nutrients that can help the development and growth of plants.

Seaweed extract is a great way to give your plants a boost - it's organic - and can be given by foliar spray or roots. It is particularly good when transplanting to bigger pots to stop plants from becoming stressed.

To help avoid blossom end rot in medium and larger varieties, a foliar spray can aid nutrient intake - calcium is crucial when plants are growing fruit - and give the tomatoes the food they need as fast as possible.

It is important to check the instructions on your plant food container to make sure that foliar feeding is possible - some feed is not suitable.

The best way to feed is little and often so that plants always have access to some food. My preferred method is to reduce the recommended amount by half and feed twice as often.

Friday, 1 May 2009

Removing Leaves

It's a good idea to remove the leaves at the bottom of a tomato plant if they are looking poorly. Pull them off with an upward yank rather than cut them with a blade because scissors/blades can transfer infection from plant to plant.

It is common practice to remove leaves from tall varieties up to the first truss. It creates more air movement around the base of the plant and gives more energy to the upper part of the plant and tomato development.