What grafting is
Grafting joins the top of one plant to the roots of another. The top — the scion — is the variety you want to sell: a particular rose, a particular mango. The bottom — the rootstock — is chosen for what happens underground: vigour, tolerance of the soil, resistance to what lives in it.
Cut both at a matching angle, press the faces together, hold them still, and the two knit into one plant. It is the oldest trick in horticulture and almost every commercial rose in Kenya is made this way.
Why roses are done slightly differently
In most grafting, the rootstock is already a rooted plant. In commercial rose propagation it usually is not. A cutting is taken and grafted in the same operation, so the join forms while the rootstock is still growing its own roots. The technique has a name — stenting — and it matters here because it means the join has to be held mechanically the entire time, under mist, with nothing underneath it yet.
That is what a silicone sleeve is for.
The four weeks, day by day
- Day −7 · Filling.
- Trays are filled and the medium settles. Fill short and you lose root volume; fill over and water cannot leave the base of the cell.
- Day 0 · The cut.
- Scion and rootstock are cut at roughly the same angle, brought into line and sleeved. From this moment nothing about whether it worked is visible.
- Days 2–7 · Callus.
- A layer of undifferentiated tissue forms across the cut. The plant cannot draw water through the join yet, so the air around the leaf has to stay wet — which is also excellent weather for disease, hence the hygiene protocol.
- Days 10–21 · Roots.
- Roots push from the base while the join is still setting. Both want the same conditions at the same time. This is the stage that separates a good propagation house from an average one.
- Days 18–24 · Weaning and hardening.
- Misting is stepped down week by week and light is raised, so the plant learns to hold its own water before it is moved.
- Day 28 · The count.
- Take is assessed as the presence of both a shoot and roots. That number is what the month was for.
What "take" means, and what it looks like in Kenya
Take is the share of grafts that produce both a shoot and roots, counted at four weeks. It is the number a propagation manager manages to, and it is sensitive to things that sound small.
Published Kenyan work illustrates the range. In a study of the rose variety 'Inca' by Otiende, Nyabundi and Ngamau (Journal of Applied Horticulture, 18(1), 2016), grafting take on Natal Briar rootstock reached 85.2 % from cuttings taken low on the mother shoot, while the rootstock 'Rosa Progress' averaged 60.0 % across the trial. Cuttings from the base of the shoot outperformed cuttings from the top on both rootstocks, and auxin treatment beat none.
Those are figures from one Kenyan trial on one variety, not a promise about your house. The point is the size of the gap: the difference between a good decision and a careless one at this stage is tens of points of take.
Where each thing we sell fits
A word on grafted vegetables
Grafting tomatoes, peppers and cucurbits onto resistant rootstock is well established in several countries and is used mainly against soil-borne disease. In Kenya it is emerging rather than established. The documented programme is run by Egerton University with Nanjing Agricultural University across 18 demonstration sites in Nakuru, Kisumu, Bomet and Subukia. We supply the consumables for it, and we will say plainly that the established, repeat-volume grafting in this market is roses and fruit trees.