When making your own cuttings, wrap them in moist paper or pack them in material such as damp peat, in a plastic bag.   Keep cuttings  refrigerated or store them in an unheated place but where they will not freeze. Freezing  will not harm them, but can take water out and dry them out.  The ideal temperature is 32-33 F. Properly stored, cuttings can be held for as much as a year. If you are ordering cuttings they should arrive packed for storage, allowing you to simply put them away until you are ready for them.

Large quantities of cuttings can be stored by burying them in pits of sand (to prevent waterlogging) on the north side of a building. They should be buried upside down with  6 -18 inches of sand over them, covered with tarps and boards. As spring arrives, some or most of the sand is removed so the bottoms of the cuttings warm and callus in preparation for planting.

Callus is the white tissue that forms on cut surfaces of the cutting, and may also appear in lines along the sides of the cutting.   It is from callus that roots form.

Callus formation (A) takes place at the bottom end of cutting, near or at the bud.   Roots (B) will begin to show a day or two later.

Typically cuttings that have been callused in a black plastic bag will have roots at nodes, and in other areas along the cutting, and thick white shoots will be pushing from buds. Callus may not always be obvious, but it must be there before roots develop. Once  roots start, they  grow in cooler conditions than are needed for callus to form.  A grape cutting  pushed into soil will just sit until the soil is warm enough for callus to form,  so it usually only grows a few inches the first year.  But by pre-callusing the cuttings before planting, they can grow much more than they would otherwise, often enough to establish the trunk of the vine.
A callused cutting planted in it's permanent location, kept weeded, watered, and well fertilized, can establish it's roots in place as it grows a top and can often grow enough to allow it to bear a cluster or two the next season.  Nursery-grown bare-root vines have to grow a year to re-establish their roots before being trained up the second year, and can finally start to bear the third year, a full year after a cutting planted at the same time.  
Before  callusing,  be  sure cuttings haven't dried in storage.  Standing them in  an inch or two of water overnight will let them "refill," and  improve rooting. There are several methods to callus cuttings, according to your situation. While rooting hormone isn't absolutely necessary, it can hasten callusing and increase the number of roots.  The product 'Rootone', is often used for this purpose  .

Method 1. Small amounts of cuttings can be callused by wrapping them in moist paper or sphagnum in a black plastic bag so if they have been stored properly, they are ready to callus.  Put them in a warm area that stays constantly at 80-85°F.  The top of a refrigerator is a good place as the waste heat from the condenser collects there.  Callusing should occur in one to two weeks. Buds may push and produce white sprouts, but this isn't harmful, though care should be taken to avoid breakage as the cutting must use energy to grow more shoots

Method 2. Plant  the cuttings in a pot of a mix of 3 parts perlite to 1 part peat, by volume.  Set the pot on a heat mat set to 85°F, in a cool area, or even outdoors in a protected area.  This heats the root zone and encourages callusing, but the top of the cuttings, being in cool air, will not push buds as readily.  The idea is to get roots before buds push too much so there is an existing root system to support the new growth when it appears. Rooting occurs in one to two weeks in most cases.  Plant as soon as the cuttings are callused and roots start to appear.

Method 3.  Plant the cuttings in a one gallon black pot of the 3:1 perlite-peat mix and set it in a sunny location where the pot can be warmed by the sun.  The pot should be no larger than one gallon as the warming effect of the sun will penetrate a larger pot too slowly.  Avoid excess watering as that will cool the mix and slow rooting. This is a slower method, often taking as much as a month, and the buds will often start to grow before the roots are formed, but it works well enough for home use.

Larger quantities of cuttings can be bundled in lots of 50 - 100 and rooted in the 3:1 perlite peat mix in benches with bottom heat (heat cables or hot water pipes) set at 80 - 85°F in the root zone. Ideally, beds should be outdoors or in an unheated, or even refrigerated, room to retard sprouting of the buds  while the cuttings callus and root, as in method #2.  This reduces the likelihood of shoots that can break off  during planting.

PLANTING

Cuttings callus and root in a short time, so don't start callusing until the planting site is ready so the cuttings can be planted immediately.  Once cuttings have a ring of callus on the base, or roots are starting to appear, it's time to plant them.

Cuttings may be planted: (1). directly in the spot where you plan to grow the vine; (2). in a nursery row where you can grow them until fall, then transplant the vine when it is dormant; (3.)  in a pot.  In the last case, you can start cuttings early in the year, then transplant them into their permanent location from the pot as spring advances, or even grow them in the pot all summer and set them out in the fall, if fall planting is possible in your area. If you lack means to keep the young vines watered in the permanent location, it is better to grow vines in a nursery or pot and transplant them as dormant vines, which are able to take more stress when they are planted in the permanent location.

Plant cuttings with half or more of their length in the soil to help protect them from drying out.  In hot, dry areas the cuttings can be covered with a mound of loose soil.  Keep watch for buds breaking through and when buds start to grow, pull the soil mound away from them.  If some of the roots or shoots break during planting, it isn't a disaster, but avoid it if possible as the cutting must expend energy to grow more.  If white shoots die or rot back a bit,  new shoots will start from the base of the old shoot.

Water an inch or more a week until the shoots get to six inches long, then start  feeding with a balanced fertilizer, such as fish emulsion (mixed according to directions) or slow release fertilizer.  Before the new shoots are about 6 inches long, the roots are not developed well enough to get full benefit from fertilizer.  If you use drip irrigation, the fertilizer can be applied in the water.  Stop fertilizing by mid summer and reduce or stop water soon after that to allow the vine to harden before frost.

GREEN (SOFTWOOD) CUTTINGS

Green cuttings are used mainly with grapes that do not root from dormant cuttings, such as varieties derived from Vitis lincecumii or V. aestivalis (such as "Norton"), or Muscadine grapes (Muscadinia rotundifolia), or when dormant cuttings are not available.  Muscadine grapes started from green cuttings have a success rate of 70 to 80% versus 1 to 2 % from dormant cuttings. Green cuttings can also be used to multiply a variety quickly.

Make green cuttings from any vigorously growing shoot.  Avoid shoots that have stopped growing and are starting to harden off  and turn brown. Take cuttings as early as possible in the spring to give the young vine extra time to harden off, unless you can keep the vine in a greenhouse.  Cuttings should be 4  to 6 inches long, with two or three leaves.  Remove all but the top leaf and cut that one in half if it is full size, but leave it alone if it is a young, undersized leaf.  Cuttings with no leaves  at all very seldom root.

A green cutting having three nodes, with small leaf left intact (A).  Green cutting with large leaf cut in half to reduce transpiration (water loss) from leaf surface (B).

Dip the green cutting in rooting hormone and plant in the same 3:1 perlite peat mix used for dormant cuttings.  The ideal place to plant is in mist bench with a heat cable in the bottom of it to hold temperatures at 85oF (25oC) in the root zone.  Done this way, the cuttings will usually root in 6-9 days and be ready to pot up.  Keep them under mist or in high humidity for a few days until the new roots can keep the plant from wilting. When held in a greenhouse and forced with extra fertilizer, the new vine can itself provide material for more cuttings within two or three weeks.  With this system of using each new batch of rooted plants as sources of more material, a few cuttings can become thousands in six weeks.
A simpler alternative is to use a one gallon black plastic pot, with a clear plastic bag over it, supported by wires and held on with rubber band  to form a humid chamber where green cuttings can  be rooted This keeps the cuttings from wilting until they root.  If the pot is warmed by sunlight,  rooting is slower since the pot cools at night and may take three weeks to a month.  If the pot is sent on a heat mat, to keep the heat constant,  rooting is faster.   Vines started from green cuttings need more protection when set in the vineyard and should have direct sunlight.  Any way you do it, your new grapes will give you pleasure for as many years as you want.

02/01/2009
[ Home ] [ Up ]