Growing Your Own Heirloom Tomatoes From Seeds

Hey Happy Gardeners,

We know growing your own tomatoes over spring and summer is a favourite hobby of many gardeners around NZ. Homegrown tomatoes, especially heirloom varieties, are on a completely different level in terms of depth of flavour and sweetness compared to mass-produced supermarket tomatoes.

We believe everyone should be able to grow their own gourmet tomatoes at home, and enjoy trying all sorts of wonderful different varieties no matter your experience. In this blog post we outline some key tips to help you be successful in your tomato growing efforts.

Prepare Your Soil

Tomatoes are heavy feeders in the garden and use lots of nutrients, so you’ll benefit from preparing the ground in advance of planting your seedlings out. Ahead of planting time make sure to remove any weeds, and then it’s a great idea to spread a layer of compost, and then another layer of mulch on top of the compost to invigorate and feed your tomato patch e.g. a few weeks before planting your tomatoes out.

Sow Tomatoes At The Right Time

Tomatoes are heat loving plants and don’t like the cold. If you’re the south of the country, be wary that the risk of frost carries into about late November so you don’t want to transplant your tomato seedlings outside until this risk has passed.

If you’re in the north island you can generally start your seeds out in trays or punnets indoors from August or September for planting out in October onwards. If you’re in the south, you will probably want to wait until October to start your tomato seeds indoors, and keep them warm until transplanting late November or early December.

Tomatoes will keep growing happily in your garden until the cold weather arrives again in Autumn, so grow and enjoy as much as you can over the warm months!

Give Your Plants Adequate Space

As a new gardener it’s easy to plant your vegetable plants too close, especially if you have a small garden. The major issue with this is your plants will then fight with each other for root space and nutrients, and then can become more prone to insect or disease problems due to a lack of airflow around the plants.

We recommend planting tomato plants about 75cm apart in full sun. Some people plant tomatoes a bit closer than this, however we recommend allowing more room for air movement and space for your plants to grow.

Planting tomatoes grown from seeds deeply in the garden

Plant Deeply

Tomatoes are plants that benefit from being planted deeply, meaning you can transplant them out deeper than the pot you have them growing in as seedlings, and where you cover its stem the plant will put out more roots, enabling a stronger root system for your tomatoes.

You’ll want to pinch off the bottom set/s of leaves from each seedling just before transplanting, and plant out up to the next set of leaves, but not so close that the leaves are touching the ground. This is a common technique with tomato growers, so don’t be afraid if you haven’t tried this with your tomatoes before.

Stake your tomato plants well when you transplant them, to avoid damaging their roots by inserting stakes at a later date. Most varieties can grow very tall so it’s important to give them support to keep them upright.

Water And Feed Consistently

Tomato plants typically don’t need watering every day especially if you have a good layer of mulch on the garden, however it’s really important to maintain a regular and consistent watering regime. Tomato plants will reward you with vigorous growth if you ensure to water them deeply regularly, for example 2 or 3 times per week.

If the moisture levels in your soil fluctuate too much your tomatoes may suffer and even exhibit blossom end rot, which is where the tomatoes get an ugly brown spot on their underside.

Remove Laterals/Side Shoots

Indeterminate tomato varieties benefit from their laterals, or the side shoots, being removed from the main stem (see highlighted image below). It’s good practice to aim to remove every lateral as likely you’ll miss some anyway, and in a matter of a few days they can grow from nothing to a fully fledged, large side shoot.

Removing Tomato Laterals / Side Shoots

You can rub/snap small laterals off carefully by hand, or use a knife to cut them cleanly (recommended for larger laterals that get away on you). Bear in mind that laterals can regrow from the same spot you’ve already removed them previously, so be vigilant this will require ongoing efforts.

A handy plus side here is that if you want more tomato plants at short notice, you can always pop a removed lateral into a glass of water to grow roots, and you’ll have another seedling to transplant out in no time!

If you don’t remove most of your laterals, you’ll end up with a messy, more disease prone plant that gets quite top heavy, and your tomato fruit will be of a smaller size. It’s okay to leave 2 or 3 laterals if you wish, however we recommend having 4 main stems maximum on an indeterminate tomato variety.

Determinate or bush-type tomato varieties are shorter plants that grow to a ‘determined’ height, and require less vigilance in removing laterals, however they can still benefit from early laterals being removed to prevent the plants from being too overgrown and straggly.

Remove Lower Leaves As Plants Mature

As your tomato plants mature the lower leaves will naturally start to die off. We recommend regularly removing the lower leaves with a clean blade as your tomato plants mature, e.g. when they lose their luscious green colour and turn light yellow, as slowly those old leaves will start to cost your plants more energy than they produce.

By removing the old, yellowing lower limbs of your tomato plants you help to prevent disease spreading up the plants, and enable them to focus on their healthy productive limbs.

Grow Appealing Tomato Varieties

When growing tomatoes from seeds you have lots of uniquely shaped and coloured options to choose from. We offer several exciting varieties with different characteristics in our collection of heirloom tomato seeds.

Amish Paste’ produces medium to large sized fruit with finely balanced flavour. It’s delicious for eating fresh, and is popular for cooking and processing into sauces and pastes. Tomato Amish Paste grown from seeds
Black Cherry’ is a gourmet tomato producing small to medium sized round fruit with black-purple colour. They’re bite-sized and very moreish, offering sweet yet delicious flavour. Tomato Black Cherry grown from seeds
Black Krim’ is a highly tasty beefsteak with dark red-purple-brown skin. Popular for its consistent performance in the home garden, it’s highly sought after at farmers markets and a favourite of fine chefs with its rich and tart, smoky flavour. Tomato Black Krim grown from seeds
Gardeners Delight’ is an outstanding variety producing small to medium sized round, red cherry tomatoes. Offering wonderful sweet flavour, they’re perfect for eating en masse. Compared to many other varieties they keep rather well. Tomato Gardeners Delight grown from seeds
Moneymaker’ is a medium sized tomato renowned for its reliability. The fruit are bright red with thin smooth skin and taste sweet without the deep tomato flavour of some varieties. Tomato Moneymaker grown from seeds
Mortgage Lifter’ is an all time favourite producing large pinkish-red beefsteak tomatoes. The hearty tomatoes are slightly flattened and can comfortably grow to 500gm and larger with good growing conditions. Tomato Mortgage Lifter grown from seeds

All of our tomato seeds are NZ grown, and we’re growing several more heirloom tomato varieties for seed this summer.

Grow Companion Plants

Many people grow Basil alongside their tomato plants, as they’re well known companion plants. Basil will help to mask the scent of your tomato plants from pests like whitefly, and is even said to improve the flavour of tomatoes grown nearby.

Marigold and Calendula are also highly useful companion plant for tomatoes, as they can attract attract beneficial predator insects that will naturally deal with pest insects for you, as well as pollinators like bees. Some other useful companion plants include Coriander, Spring onions, Chives, Parsley, and Nasturtium.

These companion plants are also helpful as they can help to shade out some of the garden while having shallow roots that don’t compete with your tomatoes.

Marigold flowers growing as companions to homegrown tomato plants

Enjoy Your Homegrown Tomatoes

Ensure to pick your tomatoes regularly once they start ripening, and enjoy the taste and price difference compared to buying tomatoes from the supermarket.

You may need to protect your fruit from birds as the tomatoes start to turn red, and if so you can either cover the whole plants with nets or cover individual fruit e.g. with paper bags.

Pick your tomatoes once they’ve fully changed colour for maximum sweetness, and eat as many as you can until you’re sick of tomatoes! Until next summer that is…

Happy growing!

Handful of black cherry tomatoes homegrown from heirloom seeds