At last, it is March. It may not be the official start of spring, but it is the start of meteorological spring -and if it’s good enough for weather forecasters, it’s good enough for me. The start of March means my seed sowing can get going properly – both in the heated propagator at home and undercover down at the plot.

There are strong winds predicted for this week and after my early beetroot sowings were knocked out of the greenhouse by Storm Doris last week I am going to leave sowing anything else at the plot for a few more days.

But over the weekend, I sowed tomato seeds in the propagator. I am trying 20 varieties this year (normally it is closer to 40, so I am being restrained). I sowed four seeds of each variety in small 5cm diameter pots. The seeds are quite small so they shouldn’t be buried too deeply but just below the surface, with a light sprinkling of seed compost or vermiculite on top. Once they grow, I will prick them out into individual pots – I will keep all of the seedlings that make it, grow one of each variety for myself and donate the rest to our allotment site’s stall at the local fete in May.

The varieties I have chosen this year are all ones I’ve grown previously. Some of them are favourite heritage and/or colourful varieties, others are just reliable croppers that will hopefully keep us in tomatoes until late September.

Some of them are F1 hybrids, which are bred for good disease resistance, germination and cropping, but the difference between them and non-F1 is that you cannot save the seeds for next year because F1 will never grow true to type. Half of my 20 are heritage varieties – and their seed can be saved for another year – in fact, it is good to do this to keep the variety going, as many will have fallen out of mainstream use.

They have wonderful names and colours, and are still at the height of tomato fashion. The downside is that they are not always good at germinating or fighting disease, but I believe it is still worth growing heirloom varieties.

Most of the tomatoes here are indeterminate – meaning they need to be grown as a cordon up a pole or string, with non-flowering side shoots removed – so I have only indicated the ones that are determinate, or bush varieties.

Here is my 2017 Tomato List:

Heritage:

‘Yellow Pear’ – no prizes for guessing the colour and shape, this tomato grew really well on my plot last year and has a delicious sweet flavour.

‘Red Pear’ – as above, and another prolific grower.

‘Cream Sausage’ – determinate or bush variety so does not have its sideshoots removing. It is not really cream-coloured or sausage shaped but pale yellow and oval.

‘Bloody Butcher’ – wonderfully named variety, it is medium-sized with blood red flesh. I tried this for the first time last year, and my seedlings were killed by a late frost, but I love the sound of it so am going to give it another go.

‘San Marzano Redorta’ – large, succulent plum variety which is great for pasting into rich Italian tomato sauce.

‘Principe Borghese’ – determinate Italian plum variety which is ideal for turning into sun-dried tomatoes as it has a high proportion of “dry” flesh to water.

‘Brandywine’ – a beefsteak variety with a deep red colour; not the most reliable cropper and needs some care if growing outdoors.

‘Pink Brandywine’ – like its darker sister, a beefsteak variety but with a blush colour.

‘Virginia Sweets’ – striped yellow and red beefsteak tomato, variable germination but worth it once you get there.

‘Marmande’ – French heirloom beefsteak which is semi-determinate, meaning it grows like a bush tomato but may need some support.

Non-heritage but still with interesting colour/stripes:

‘Indigo Blue Berries’ – a cherry type which turns purple at first and then almost black with red undertones when ripe, the colour makes it rich in anthocyanin, an antioxidant.

‘Chocolate Cherry’ – another cherry tomato with a purplish-brown colour and high anthocyanin levels.

‘Tigerella’ – medium-sized with yellow and red imperfect stripes

‘Golden Sunrise’ – bright yellow medium-sized variety that I have grown every year for more than a decade, it is one of my all-time favourite tomatoes.

Red cherry, mid-sized:

‘Red Cherry’ – a very sweet cherry tomato.

‘Shirley’ – one of the best-known varieties, an F1 hybrid (meaning its seeds will not grow true), reliable cropper.

‘Sweet Million’ – small cherry tomato with prolific fruit, F1.

Plum:

‘Milla’ – a small plum variety.

Beefsteak/larger sized:

‘Beefmaster’ – F1 variety with large fruits that are ideal for stuffing and is happy to grow outdoors.

‘Big Mama’ – large plum F1 variety which is also excellent for making into sauce.

Once each seedling has grown two true leaves – beyond the first seed leaves – I will prick them out into individual 5cm pots and move them out of the propagator as they no longer need the intense heat, to a warm windowsill.

In early April, once the risk of late frost has passed in London, I will move them to the plot but keep them in one of the plastic greenhouses. By late April or early May it will be warm enough for them to go outside. Like last year I am going to grow my tomatoes in 25cm pots. They should be ready to harvest from August.