Crop Focus: Tomatoes, Part 1
Tom tom tomatoes!!
Nothing quite spells summer in the garden like a sun-warmed, flavoursome tomato! But oh - quite a journey to get there!
Ok here is tomato 101:
There are two very broad types of tomato, based on how they grow:
Determinate This means bushy, short tomato plants
Pro’s: fruit earlier, don’t need staking unless on a very windy site, can be grown in a container.
Cons: prone to damage from banded rails and rats on Aotea as fruit are close to the soil
Indeterminate: Tall tomato plants that need staking
Pros: keep growing and producing for a long time as long as staked and regularly fed.
Cons: need staking ie structures to support the plants.
Then there are the different sizes and shapes of fruit:
Cherry toms: small round fruit; can be planted earlier than their bigger relatives; usually prolific producers
Grape toms: small elongated fruit, (just like grapes), usually prolific
Beefsteak toms: large rounded or flattened fruit, great for slicing.
Plum/Italian: long plum-shaped tomatoes, usually less seed so good for sauce
Oxheart: pear-shaped toms, skin pinkish red, few seeds, low acid, very sweet
Finally, tomatoes come in a wide range of colours and flavour: ALL of the variations above come with red, yellow, orange, greenish or purple/ black fruit! Even striped!
Adding colour to your diet is really important for health and well-being, so step on the wild side and try growing some coloured tomatoes this year!
Red tomatoes contain lycopene, the phytochemical that gives tomatoes their red colour. However lycopene is not well absorbed by the human body, and red tomatoes need to be cooked to make the lycopene more bioavailable.
Orange tomatoes have a different form of lycopene, called cis-lycopene, which is 8 ½ times more absorbable than red lycopene. They can help prevent heart disease, and certain types of cancer like prostate cancer. They tend to be very sweet and rich-flavoured, lower in acidity than red tomatoes. “Black” varieties have dark skin and dark green seed gel and have a smokey, tangy flavour.
TIP: Free seeds of orange varieties proven to contain cis-lycopene can be ordered from Heritage Food Crops
Heritage Food Crops: Heirloom tomatoes
GROWING TOMATOES
Tomato Bed Preparation and Feeding
Tomatoes are known as heavy feeders… makes sense when you consider how much fruit they can produce.
This means they need rich soil.
To your tomato bed, add plenty of:
Compost (at least a double handful per plant)
Ground-up eggshell or milk powder (for calcium)
Seaweed meal/liquid seaweed fert - apply weekly when fruiting starts
Fish meal/liquid fish fert - apply weekly when fruiting starts
A large handful of neem granules (to deter the Green Vegetable Bug aka Green Shield Beetle)- reapply monthly
Rock dusts can add minerals but this will be at a slow release rate that relies on microbes to make the nutrients plant available
Planting Tomatoes
Space your tomatoes at least 60 cm apart. This summer there may be alot of heavy rain if a La Nina forms, so the key is to reduce humidity.
Plant tomatoes DEEP! Remove the lower 3-4 leaves and any laterals and plant on a slight angle, 3-4 cm deeper than in the pot. The tomato will send out new roots from the stem, which will make it stronger against wind. The extra roots will acess more nutrients.
Mulch the beds
Apply a heavy thick mulch of whatever organic matter you can get around the tomatoes; this will conserve moisture, keep weeds at bay and feed the soil. Keep the mulch away from the stem itself to avoid the possibility of stem rot.
Pruning/Delateralling and De-leafing
Removing laterals on a tomato plant serves several purposes.
First, having less foliage means
less humidity around the leaves (which can foster diseases)
less opportunity for bugs such as the psyllid, corn ear worm and green vegetable bug to lay their eggs
Secondly, the tomatoes that develop from the main stem will be bigger
It is best to remove laterals while they are still small, as this causes less damage than snapping off big long shoots. Also energy will be channeled into the main stem. Avoid using a knife or snips- just snap the lateral off by hand.
Remove lower leaves and continuing to do this as the tomato grows keeping around 10 leaves only. This will not reduce the fruit but will keep your plant healthier.
BE CAREFUL NOT TO REMOVE FLOWERING TRUSSES - THESE COME DIRECTLY OFF THE STEM AND CAN BE HARD TO DISTINGUISH FROM LATERALS AT THE TOP OF THE PLANT!
Try to remove the laterals and leaves on a weekly basis.
Bush tomatoes do not need to be pruned.
Tomato seedling before pruning.
Several laterals, larger at bottom as they formed first.
Grasp lateral close to stem and snap off sharply and firmly.
Small scar where the lateral was removed.
Snap off lower leaves usually snapping upwards avoids tearing.
Tomato seelding has been pruned. Repeat weekly!
At the top of the tomato there are often flower heads as well as the main shoot which will keep the plant growing upwards, and sometimes a second leader, which will cause the tomato to have two main stems if allowed to grow.
MAKE SURE TO LEAVE AT LEAST ONE LEADER AND DO NOT REMOVE FLOWERS!
Watering
Avoid wetting leaves of the tomato plants and try to water in the morning or late afternoon, rather than the evening to reduce humidity. As fruit develops, water deeply 3-4 times a week. If you have enough water, setting up drip irrigation under your mulch will keep the soil evenly moist and conserve water.
Companion Plants
Alyssum is one of the best companion plants to have around any of the solanaceous family. It goes to flower early which is what you want, as the small flowers provide nectar for several beneficial insects which will eat the eggs, larvae and adults of the pest insects that affect tomatoes. Alyssum also takes very little from the soil and forms a ground covering mat which will help to keep the soil moist.
Basil is often recommended as a useful tomato companion - just make sure not to plant it too close to your toms- basil plants can get big!
Read the article on companion plants to find out which other plants are useful to attract beneficial insects.
