Steward Farms · Marietta, Georgia

The Lab

We grow our own blackberry plants — clean, true-to-type, started from a piece of cane the size of a grain of rice. Here is how it works, and why a small family farm bothers to run a lab at all.

Why We Do It

A berry farm that grows its own plants

Most small farms buy their planting stock from a wholesale nursery and hope it comes in clean. We decided to grow our own instead.

The method is called tissue culture, or micropropagation. A tiny piece of a blackberry stem — a single growth bud — is surface-cleaned and set on a sterile nutrient gel inside a sealed jar. Done carefully, the young plant starts life without the viruses and diseases that quietly build up in field stock over the years. And because every plant is grown from the same mother tissue, they are all genetically identical — the exact variety, true to type, every time.

It is the same approach universities and large commercial nurseries use to produce clean stock. We just do it at kitchen-counter scale, with the varieties that have already proven themselves on our own ground in Marietta.

The lawn is a liability. The berry rows are an asset. So is knowing exactly where every plant came from.

What's Happening in the Jar

One bud becomes a hundred plants

Inside that sealed jar, a single node wakes up and begins to push a cluster of new shoots. Every few weeks those shoots are divided under a sterile work box and moved onto fresh gel. A small handful of clean starts turns into dozens, then hundreds — each one a copy of the last.

A blackberry node in tissue culture pushing new green shoots inside a sterile jar at Steward Farms
A node waking up · new shoots forming
Multiplying blackberry microshoots in tissue culture at Steward Farms Marietta Georgia
Multiplication · one start, many shoots
  1. Start clean One growth bud is cleaned and placed on nutrient gel in a sealed, sterile jar.
  2. Multiply The bud pushes shoots. Every few weeks the shoots are separated and moved to fresh jars — the batch grows on itself.
  3. Root Once there are enough, shoots are moved to root, either in the jar or straight into a rooting bed.
  4. Harden off Rooted plantlets are weaned out of the sterile world the same way any transplant is — humidity dome, mist, shade, then sun — until they are ready for the ground.

Start to a plantable blackberry is roughly five to six months.

The Setup

A still-air box and a shelf of jars

There is no institutional lab here. The whole operation is a sterile work box, a pressure canner to sterilize the media, and a wire rack under LED grow lights in a climate-controlled room. The culture vessels are half-pint canning jars.

Every batch is logged — how many starts went in, how many stayed clean, how many shoots each one produced. The contamination rate drops and the yield climbs with each round. That record is the real asset: a repeatable process, written down.

Steward Farms home tissue culture setup — jars of blackberry cultures on a wire shelf under LED lights in Marietta, Georgia
Cultures under lights · Marietta, GA · 2026
Where This Is Headed

Clean plants, grown here.

For franchise partners, this is where your plants come from — the same genetics and the same standard at every site, not whatever a catalog has in stock that year.

For gardeners and growers, a limited number of plants will be offered locally once the first batch is weaned and ready. We are not selling plants yet — the list gets first pick.

Get on the Plant List See the Franchise

Plant availability will be local pickup in the Marietta area. No shipping at this time.

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Batch updates, the good jars and the contaminated ones, and first word when plants are ready — live from the farm.

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