San Marzano Determinate Tomato Seeds


San Marzano tomatoes are the quintessential Italian sauce tomato. This admired heirloom variety has its origins in the volcanic soil at the foot of Mt. Vesuvius in San Marzano sul Sarno, a small town near Naples. The name San Marzano is a matter of local pride, as they are only produced in this specific region after receiving a protected designation of origin certificate.

Determinate San Marzano tomato plants produce heavy yields of fruit efficiently, with little to no maintenance required. One heavy duty stake is usually sufficient to stabilize the central stalk. Pruning is not required because all the set flowers will produce and ripen within a small harvesting window. Be sure to have a plan to deal with a mass of fruit all at once! To lighten the load of an overwhelming harvest, pluck off tomatoes once they begin to ripen at the blossom end.

Although quite comparable to Roma tomatoes, San Marzano are thinner, coming to a prominent point at the bottom. San Marzano are comparatively sweeter and less acidic. It’s for good reason these tomatoes are ubiquitous in the canning industry. The symmetrical shape and hollow seed cavity make them a snap to process. The firm flesh is ideal to cook down into marinara sauce or paste. Also fantastic for freezing and roasting, the teardrop-shaped fruits are easily recognized and esteemed for their flavorful meaty flesh that yields very little juice. Pizza and pasta lovers will rejoice after growing San Marzano tomatoes in their garden!


- Latin Name: Solanum lycopersicum
- Life Cycle: Annual
- Days to Maturity: 75-85
- Planting Depth: 5 mm - 1 cm
- Plant Spacing: 45-60 cm
- Row Spacing: 120 cm
- Growth Habit: Determinate


For most folks, tomatoes are an indispensable summer fruit. There are scores of heirloom varieties showcasing different shapes, sizes, colors, flavours and textures. Tap into this large selection when starting from seed. You have the ability to grow and eat your perfect tomato!

Start seeds indoors 6-8 weeks before the last spring frost date. In flats or individual pots, plant seeds at 1 cm. Make sure soil stays warm and moist. The ideal temperature for germination is 21°C. Keep seedlings under lights, a few centimeters away from the top of the plants and adjust as needed. An oscillating fan will provide the young plants some resistance. This will result in stockier stems and more structurally sound tomato plants. Seedlings should be hardened off a week prior to transplanting.

When the soil is 16°c and all danger of frost has passed it is time to transplant. Pinch off any sets of lower leaves that are yellow or faded so more of the stem can be buried. Place roots deeply into the hole to the point that the bottom leaves are just above the surface of the soil. Roots will sprout from the stalk and provide a stronger base for the plant.

Provide a site with full sun and well-drained soil. Water well, about 5cm/week, mulch and feed every two weeks. Leave fruits on the vine to ripen as long as possible.

There are two main categories of tomato plants: determinate and indeterminate.

A determinate tomato is a bush-type plant, usually reaching about three to four feet tall, making them ideal for the small-space gardener. The fruits of a determinate tomato plant ripen all at once, which is useful for those who want to grow tomatoes for canning.

Indeterminate tomatoes grow continuously until the first frost and can reach six to twenty feet in height. Indeterminate plants produce tomatoes all season long for a continuous harvest.

If indeterminate varieties are being grown, be sure to set up tall trellises or cages to support the wandering vines. One sturdy stake and some twine should suffice for determinate varieties.

Tomatoes can easily be frozen whole, but never refrigerate a tomato. This will deteriorate its fresh garden taste and texture. Enjoy fresh throughout the season and make multiple batches of sauce and salsa to savour through the winter.


- The ancestor of the tomato is native to South America, where the wild versions are the size of peas. The Spanish first introduced tomatoes to Europe during the 1500s. Unique varieties were developed over the next several hundred years to improve production, size, shape, colour, and flavour.

- Tomato seeds will remain viable for 5 years if stored in a cool, dark place, ideally between 4 and 10⁰C. After that, the germination rate may start to go down.


You know that a lush, fruitful garden needs good soil, frequent watering, and sunlight to grow, but it’s the seeds that really make the harvest.

Picked and bagged for 2024 the vast majority of our seeds have germination rates of over 85%. The seeds are all-natural, non-GMO, non-hybrid, untreated, and open-pollinated for seed saving.

We have put a lot of thoughts into the design and packaging of our seed packets. Our seeds are all carefully packed in food grade kraft paper/aluminium zipper lock bags, and then are shipped in eco-friendly padded mailers.

We heat-seal each of our seed packet for even more protection from moisture, odour and light, allowing you to store your seeds for up to 3x longer than paper or plastic. Plant them all, germinate some indoors, save some for next season - it’s up to you!

Customer Reviews
4.6 Based on 5 Reviews
5 ★
4 ★
3 ★
2 ★
1 ★
Write a Review

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

Filter Reviews:

Arrived quickly and as described. Not able...

Arrived quickly and as described. Not able to start them for a few more weeks so I cannot comment on how good the seeds actually are.


Arrived quickly and as described. Not able...

Arrived quickly and as described. Not able to start them for a few more weeks so I cannot comment on how good the seeds actually are.


great service, thank you much

great service, thank you much


My order came on time, but I tried to keep...

My order came on time, but I tried to keep them until next Spring because it's late now to germinate them!


Arrived quick, great price and selection!...

Arrived quick, great price and selection! Very satisfied.