Diary of a Greenhouse Gardener Part 11: It’s amazing how fast the tomato plants grow!

Its 8’oclock in the evening and I’m sitting in my greenhouse wondering where the year has gone. It seemed only yesterday that I was sowing my trays of tomato seeds and pots of cucumbers. My tiny seedlings are now nearly all taller than I am, especially the cucumbers which are easily 6ft tall and have already given me half a dozen sweet tasting fruits.

As promised in an earlier blog, I have been much more organized this year. I have used much taller and more robust canes to support my tomatoes and the cucumber is being trained up a 6ft length trellis, which leans from the raised bed to the side of the greenhouse frame.

The idea with the trellis is that as the cucumber grows the plant can support itself on the trellis and the fruit hangs down and can be picked from both sides.

I sowed my first tomato seeds on the 7th of March, the cucumbers about 2 weeks later. The depth of the raised bed allows the roots of the tomato plants to grow deeper than those grown in pots or grow bags, which increases their capacity to absorb water and prevents the plants from drying out as quickly. I used my own compost for the raised beds, which I’d managed to produce from last summer’s grass cuttings and vegetable waste. I also added a slow-release fertilizer to the compost to give the plants a bit of a boost.

As the weekends allowed me freer time, I allocated Sundays as my day to do a spot of tomato housekeeping. Side shoots that developed between the main stem and the side leaves are pinched out and the main stems tied into the canes.

During some research I read that it is advisable to tie in the stems above a developing flower truss as this will support the weight of the fruit better as they develop. It is worth being careful not to tie in very new growth at the top of the plants as it can be very fragile and snap. Whatever is being used to tie in the stems must also be quite loose as I discovered, as the plant stems thicken the tie can act like a tourniquet, stopping water and nutrients getting up the stem and effectively killing the top of the plant.

This picture was taken on the 9th of May just after the tomato and cucumber plants were planted out.

This picture was taken on the 29th of May. This shows the growth of the plants in just 20 days.

After the first flower trusses appeared I added a liquid feed to their Sunday watering can. I have been adding the feed once a week according to the manufacturer’s instructions, but some people like to add a more dilute feed to the water daily. One of my gardening clients has been making his own feed from comfrey leaves which he steeps in a barrel with a tap at the bottom, he then drains of the liquid and dilutes it to his own recipe. This feed is said to be very high in potassium, so good for fruit production, but it is rather smelly.

The lovely warm weather has really helped to accelerate the growth of all the plants in the greenhouse. The peppers and chilli plants are starting to produce fruit, and the tomato and cucumbers are laden.  As the tomato trusses have grown, I have removed some of the lower tomato leaves to allow more air to circulate and for better light penetration, this helps the fruit to ripen more easily. The lower leaves are gently pulled off, rather than being cut, as the damage to the plant heels more quickly and there is a lower risk of any infection. 

This picture was taken on the 26th June, and the tomato and cucumber plants have easily doubled in size. Some of the tomato plants are so tall and have multiple trusses of fruit and flowers that I have decided to “stop” them. Last year I didn’t do this and ended up with lots of unripened fruit. Stopping the plant is the process of pinching out the main stem, so that the plant puts more energy into developing the ripening fruits than into growing new trusses. It may be a little early in the season to do this, but the plants should still develop new side shoots and keep actively growing.

Whilst browsing in my local garden nursery yesterday, I came across a melon plant, which according to the label can be grown in a greenhouse. I have tried to grow melons outdoors in the past but have never managed to produce any decent sized or ripened fruit. So as a bit of an experiment I thought I would give growing one in the greenhouse a try. I’ll let you know how I get on.

Text & photos: Sian Napier