Monday 27 April 2009

Rain Again!

Well ... I guess I shouldn't complain because we've had several days of sunny weather and one of my tomato plants, Red Alert, has just started to set fruit - the first flower has faded and a tiny pea-like tomato has appeared!

I did sow the seed for this plant in February so I guess it's not surprising for it to be at this stage, at this time of the season. However, not all tomato plants will set fruit in cool temperatures which is one reason why Red Alert is an early variety.

It's not just the amount of time it takes from seed to fruit, it's also the ability of a variety to "set" - that is, pollinate flowers to become fruit in cool temperatures - that makes a variety early.

Many larger varieties that originate in Italy for example, will not set fruit so early in the season because of temperature, humidity and length of day - all of which tomato "set" responds to.

Of course temperature and humidity can be controlled in high-tech greenhouses, and duration of day can be controlled by artificial light also.

So if you want an early tomato variety, the ability to set fruit in low temperatures is important. Red Alert and Glacier are two good examples.

By the way, do keep them out of the rain at this time of year if possible.

Sunday 26 April 2009

Tomato Plant Roots & Water

Looking after seedlings and young tomato plants can be a tricky business.

Just how much water to give, especially if new to growing tomatoes, can be a difficult decision to make. The method is to keep the compost just moist so that it is neither wet or completely dry.

This is actually impossible as compost or soil drys-out rapidly on a hot day, and if you are away from the house your little plants could be dying of thirst in the hot sun.

The first thing to understand is that the more water you give your plants (over a period) the less roots they will grow. This is owing to the fact that roots need air as well as water and a consistently sodden soil will stunt root growth owing to lack of air.

That means if you over water your plants, when the time comes that they need a good root system to absorb water on a hot day, they may not be able to take up all that they need.

This a a pic of a variety called Glacier and it has a good root system with strong, thick white coloured roots.

When plants are in pots they should be stood in a tray of water for 5 or 10 minutes to thoroughly absorb water and soak the whole of the compost area.

It's best to not water again until the compost is almost dry to allow air back into the soil.

If the leaves start to wilt that will be a sign that you have left them a bit too long without water! For a quick recovery, spray them with a mist of water and water them from below again.

I realise that this can be time consuming if you have to keep your eye on the plants and try to judge how moist the compost is just below the surface!

However, the best start a plant can be given is a good root system and this will pay-off with a healthy life and a good harvest.

More about watering and feeding tomato plants here.

Thursday 23 April 2009

Weather - Good or Bad for Tomatoes

Today, we've had some really good weather for growing tomatoes. Lots of hazy sunshine with a nice floating cloud or two for the odd bit of temporary shade.

I think the biggest threat to my plants at this time of year is damp wet air. I can keep them out of the rain but I can't control the humidity or condensation which can be almost as bad as rain, especially if they are slightly over-watered.

The only moisture that I like on tomato plant leaves is when spraying a mist of water to foliar feed or to revive a plant that has been in hot sunlight and has started to wilt.

It is a "given" that tomato plants hate wet leaves, that is leaves that are wet for more than a few hours, which may lead to fungal diseases such as damping-off (when seedlings shrivel and die) or tomato blight on older plants.

Fugal spores may also be found in compost that has been left in the rain outside a garden center from last season - try to make sure that the compost you buy is this year's supply.

More information about growing tomatoes may be found on the tomato growing tips page.

Monday 20 April 2009

Tomatoes & Full Sunshine

It is generally accepted that tomato plants require lots of direct sunlight in order to grow to their full potential. This is both true and untrue depending on the variety, growth habit and age.

A variety such as Tumbling Tom in full sunshine for most of the day will struggle to absorb enough water through its roots to replace the moisture evaporating through its many leaves when it is in hot, direct sunshine.

A variety such as Red Alert, which has less leaves, will need less water to supply to its leaves and therefore cope better in hot sunshine. It is also the case that a plant with a well developed root system will cope better in all conditions and produce a better crop.

Varieties that originate in Southern Europe, such as Italian and Spanish varieties, will do better in hot weather than those that come from cooler areas of the world.

I'm writing about this subject because, in the UK, we are in the middle of some very sunny and warm weather and some of my tomato plants are wilting in the hot sun!

When this happens I'll move them into the shade and give their leaves a spray misting with water ... twenty minutes later they'll look a lot happier.

It is also true about tomato plants that some varieties need to be acclimatised to direct sunlight. No ... this is not April the 1st ... it's just that tomato plants have huge divergences in growth habit and requirements which make growing tomatoes all the more interesting and rewarding.

Sunday 19 April 2009

When To Transplant Seedlings

Transfer the seedlings to their own pots when they start to grow their first true leaves - the ones between the seed leaves - see below:

Should Seedlings Be Fed?

If you use good quality new compost, you do not need to feed them until they are much bigger - when they start to fruit. However, they will need to be potted-on after about four weeks or so. That means more compost which contains more food.

If you want to feed them at this early stage, you could give them a "one off" feed - when potting-on - at half the recommended strength as on the box of general purpose plant food.

Tomato feed should only be used when the plants are fruiting because it contains mostly potash for fruit development and not the nitrogen and phosphorus for the growth of young plants.

Saturday 18 April 2009

Watering Tomatoes

The amount of water you should give tomato plants depends on the temperature and the size and amount of leaves your plants have.

Generally, the soil or compost should be just very slightly moist so that the roots have access to both water and air. Many people over-water tomato plants thinking that they're being kind, but actually too much water stunts their root growth and slows down their development.

It's best to water in the morning so that your plant doesn't have to sit in wet soil over-night when the temperatures are low. If you didn't water the plant enough, its leaves would start to wilt - if they do, give them a mist spray of water.

Perhaps the most important thing is to make sure that the entire area of the soil that the roots are in is slightly damp - dry areas will prevent access to the food the plant needs.

Hope that helps ... watering tomatoes can sometimes be a problem for even the most experienced tomato grower!

Friday 17 April 2009

First Tomato Post of the Season

Well ... I almost decided not to start-up again this season but I couldn't resist it!

My intention this season is to stick mainly to bush, cherry tomato varieties, such as:
Tumbling Tom
Garden Pearl
Red Alert
Maskotka
100's & 1000's
Minibel

To name a few, but I'm also growing a few larger varieties including Oregon Spring.

Around the end of January I sowed a couple of Tumbling Tom seeds and these plants are now flowering along with two red Alert plants that I sowed at the beginning of February. It's best to sow plants that are to be grown outdoors at the end of March - but I just can't help it!

Anyway, if we get some reasonable weather, the first tomatoes should be ready to eat around the end of June.

More about growing tomatoes from my website at: http://www.tomatogrowing.co.uk