Organic 'Mission Mountain Grex' tomato
Organic 'Mission Mountain Grex' tomato (Solanum lycopersicum) from the seed company Gaia, a collaborative and evolving Grex variety with infinitely varied colours, shapes and flavours
The 'Mission Mountain Grex' tomato is a living, evolving variety deeply rooted in the open source seed (OSSI) philosophy. Originating from the work of William Schlegel of Montana and cultivated and then adapted in the Ottawa region by the EFN, this tomato population is a ' grex' , meaning a deliberately diverse genetic mix where crossbreeding is not only possible but encouraged. Indeterminate and vigorous, it combines lines such as 'Big Hill' , 'Dwarf Mocha's Cherry' , and 'Purple Zebra F1' , as well as disease-resistant currant tomatoes , creating a collection of exceptional phenotypic richness.
The plants, primarily F3 but also including some F2 and F4 generations, express a wide range of fruit shapes: round, elongated, ribbed, cherry, or small plum ; colors ranging from yellow to red, pink to purple , sometimes adorned with vibrant stripes or subtle anthocyanin gradients. Flavors vary from sweet and fruity to tangy and bright, making each plant a discovery. This Grex is also a fantastic area of exploration for breeders, as it exhibits high crossbreeding potential , particularly through lines such as Mission Mountain Sunrise × Big Hill or Mission Mountain Morning × Aztek .
'Mission Mountain Grex' is an ideal variety for those who wish to participate in the selection themselves, observe the diversity, select the best individuals or simply enjoy original, local and resilient tomatoes.
Companion plants : Basil, parsley, carrot, asparagus, alliums, celery, borage, marigold, calendula, mint, sage, peppers, dill (until mature)
Negative plants : Potato, corn, kohlrabi, beetroot, fennel, peas, squash
Spread/Carry : Indeterminate, vigorous
Plant height : 120 to 150 cm
Quantity per packet : 25 seeds
Certification : Certified organic by Ecocert Canada
Special features : Grex OSSI is an evolving species, exhibits extreme diversity of shapes and colors, has high crossbreeding potential, and is highly resilient to local conditions.
Farming method
Sow indoors 6 to 8 weeks before the last frost. Bury the seeds 3–6 mm (1/8–1/4") deep in a light potting mix and maintain a temperature of 23–29°C to ensure germination in 5 to 10 days . During hardening off, reduce watering and nitrogen application to encourage the plants' natural vigor.
Transplant outdoors when there is no longer a risk of frost. Space plants 60 to 90 cm (24 to 36 inches) apart, with 120 to 180 cm (4 to 6 feet) between rows. Provide full sun (level 3) and regular watering (watering level 3) . Sturdy staking is necessary to support the variety of growth habits and abundant production.
Harvesting and preservation
Harvest when the fruit has fully developed its color—this varies from plant to plant. To get a head start, pick tomatoes that have already begun to color , then let them ripen off the vine at 22°C or higher . Store them between 12 and 21°C , at 95% relative humidity , to preserve their freshness.
Usage ideas
• Perfect for multicoloured salads , where the diversity of the grex is fully expressed
• Ideal for selecting your favorite lines and developing your own local varieties
• Superb on tasting platters , each fruit being a surprise
• Excellent for salsas and creative cuisine , thanks to the variety of textures and flavors
The 'Mission Mountain Grex' tomato is much more than a variety: it's a living project, an invitation to diversity and participatory breeding. A unique horticultural experience, ideal for curious gardeners, amateur breeders, and anyone who wants to grow a resilient, free-spirited, and unpredictable tomato.
