Grafts, hothouses, spring spuds
When growing grafted plants, it is easy to forget that vigorous root stocks can sprout and grow branches of their own. This deprives the scion, or foliage above the graft, of sustenance, and it fades and dies.
So, check grafted plants, including citrus and high health roses, for any unwanted growths below the scion, and remove them.
The root stock is part of a plant, usually an underground part, from which different above-ground growth can be produced. It will have an established, healthy root system onto which a cutting or a bud from another plant is grafted.
This grafted part is usually called the scion. It has desirable above-ground properties for photosynthetic activity, fruiting or decorative purposes.
The root stock is selected for its interaction with the soil, providing the roots and the stem to support the new plant, obtaining necessary soil water and minerals along with pest, disease and drought resistance.
After a few weeks the tissues of the two parts will have grown together, eventually forming a single plant. After some years it may be difficult to detect the site of the graft although the plant always contains the components of two genetically different plants.
The root stock may be a different species from the scion, but as a rule it should be closely related. For example, many commercial pears are grown on quince root stock.
Serial grafting of several scions may also be used to produce a tree that bears a number of different fruit cultivars, with the same root stock taking up and distributing water and minerals to the whole system. Those with more than three varieties are known as family trees.
This month’s preparations for spring include tidying up gardens and glasshouses.
If your glasshouse is clear of plants, burn some sulphur powder to kill all the pests that are waiting for warmer days. Treat the soil with Terracin Soil Pathogen Suppressor, and three weeks later with Mycorrcin.
To beat the potato psyllid, get in an early potato crop before the pests start for the season.
In a deep trench place a small handful of sheep pellets, a table spoon of gypsum, a teaspoon of BioPhos and a sprinkling of Neem Tree Powder, and cover with a little soil before placing the seed potato – shoots pointing upwards – on this ‘‘bed’’.
Cover so shoots are under about 10mm soil.
Check regularly and when the shoots poke through, cover with another 10mm soil. This protects them from any frosts.
Keep doing this until the trench is full, then start mounding up. Potatoes should form all the way up making for a heavy crop. Protect the foliage from any late frosts with a spray of Vaporgard, or use frost cloth or sacking.
Early potatoes planted now will be ready before Labour Weekend and should be free of psyllid damage. Either harvest the lot then, or cut the tops off so the pests can’t damage the crop.
Problems, ring me at 0800 466464 (Palmerston North 357 0606) Email firstname.lastname@example.org Web site www.gardenews.co.nz
An apple tree stem showing where the foliage and fruit bearing scion is grafted to the root stock. It is important to keep the root stock free of any unwanted wayward sproutings.