What do you think of when you think of Italy? For me it is holiday memories, fields and fields of sunflowers, sitting on the edge of the Leaning Tower of Pisa, Pompeii and Herculaneum and the most memorable part of the whole day (I’m almost embarrassed to say) was eating lunch in what I think was little more than a small garage with a wood fired pizza oven in the back which served the most amazing pizza Napolitano
If you have had a proper Italian pizza then chances are that the sauce was made from San Marzano tomatoes which are so highly prized by the Italians that it has a PGI (protected geographical indication) which is similar to the French wines appellation d’origine controlee and controls where food such as Cornish pasty’s, champagne and parmesan can be produced and still use the name. Indeed people from Naples will say that you cannot make a Napolitano pizza without only using San Marzano. The tomatoes command such a high price that counterfeit cans of San Marzano are actually a problem.
So what is the big deal?
Having grown them for several years I can see why the Italians rave about them. They are a good mix of yield and taste, plants are fairly healthy especially as the middle of England is hardly Southern Italy. They cook down to a nice pulp, not many seeds and if you choose to remove the skin then it is fairly easy to do so. They aren’t however the best tasting paste tomato I have ever grown, that is Amish Paste.
San Marzano is a cordon tomato so needs to be trained. It is also best grown under glass but can be grown outdoors. Unless you live in the designated area for those who make a living from their land, you cannot sell any tomatoes you grow as “San Marzano”.
In the kitchen: San Marzano is a plum tomato that is used exclusively for cooking, mainly for sauces or pizza toppings. It is one of the best flavoured paste tomatoes you can grow, has very few seeds, has easy to remove skin if you need to and cooks down to a deep rich pulp.
Yield and plant health: It has smaller yields than it’s offspring Roma but makes up for it with it’s more intense flavour. Plant’s I’ve grown have been general healthy and crop over a long period. It is often grown as a greenhouse tomato as being first bread in the Naples area it is a heat lover. Stress can cause blossom end rot and it is worth slicing every fruit before making paste as some develop a calcified black area where the seeds are, possibly anthracnose although I have my doubts as it is limited to the San Marzarno. The black core can be cut out easily and the remainder of the tomato is unaffected.
Grow Again? Every year
Widely available in garden centres but also available online
Sow tomato seeds from January (for greenhouse/conservatory tomatoes) to April (outdoor tomatoes) and keep at a temperature of 18 a 20 degrees c. Germination should take 7 to 14 days.
I sow 6 seeds in a small seed tray, making sure there is at least an inch between seeds. I then cover with half a centimetre of vermiculite, water and place in a heated propagator in a location that receives plenty of light.
Once your tomatoes sprout the challenge is to give them sufficient light to stop them getting leggy. A sunny window ledge in a cool room, a heated conservatory or greenhouse kept above 12 degrees c are ideal. You will need to turn tomatoes grown on a window ledge often as they will grow towards the light. You can also use LED grow lights to supplement the light they get. Gently blowing the leaves daily may also encourage them to be more stocky.
When the seedlings are large enough to handle (2-4 leaves), transplant into individual 3 inch pots. Pot on as required. Plant out, 2-3 ft apart after al risk of frost has passed.
Cordon tomato plants require support from about 4 inches. They will then need further tying in as the plant grows. Pinch out the side shoots that grow between the stem and the leaves before they reach 2cm long. Take the tops off outdoor tomatoes after two trusses have set fruit. In unheated greenhouses after 4 trusses and in heated green houses, stop in September to allow remaining fruit to ripen.
When tomatoes are young keep the soil moist but not damp. Water from the base to reduce humid you around the leaves which encourages blight. As they start to fruit you will need to keep them consistently watered, daily if necessary to prevent fruit putting sudden spurts of growth on and splitting.