Plant Answers

THE APPROACH GRAFT
AN ECONOMICAL, EFFECTIVE SOLUTION

"My plant is yellow! What can I do?" If I had a nickel for every time that I have heard that complaint I would be a rich man. Yellow plants seem to be a way of life in this area. Most yellowing of plants, if pests are not involved, is caused by lack of iron in the plant. Such an iron deficiency in a plant can be caused by the plant's inability to utilize available iron in the soil or simply the lack of iron in the soil. Because most soils in this area of Texas contain an abundance of calcium which causes an alkaline soil condition, many of the minor elements such as iron are not in a usable state for plant consumption even if they do exist in the soil. As a rule, iron deficiencies tend to diminish as temperature increases and soil moisture decreases. Improved aeration encourages greater microbiological activity with greater root growth and exposure to soil iron. For more information about curing "the yellows", see:

http://www.plantanswers.com/garden_column/may04/3.htm

But unadapted plants NEVER recover regardless of temperature or moisture. Without extensive soil amendments, gardenias, azaleas and blueberries will be eternally yellow and shrink instead of grow.

Some of our most treasured, fruiting plants suffer from iron chlorosis. Citrus, grapes, peaches, pears and apples can turn yellow and eventually perish because of iron chlorosis. One of the best defenses against iron chlorosis is to plant adapted varieties. Plants which are native to the alkaline soil conditions have the ability to extract enough of the sparse and tenacious iron molecules to avoid the yellowing, weakening effects of iron chlorosis. If these adapted plants can be utilized, addition of iron, acidification of the soil and the constant struggle to maintain a green plant color can be alleviated if not totally eliminated. These adapted, native plants also have resistance to soil-borne pathogens which can annihilate non-indigenous types.

Unfortunately most of the adapted native species do not produce as good quality fruit as desired. For optimum growth and quality production, a combination of native and improved must be accomplished. Such combinations are accomplished by grafting. Unfortunately grafting is a skill which most of us do not possess or, if we have tried it, are not extremely proficient. There are many things which can go wrong when grafting, any one of which can insure failure. There is only one surefire technique. This grafting technique is fail-safe. It is referred to as approach grafting.

The distinguishing feature of approach grafting is that two independently growing, self-sustaining plants are grafted together. This self-sustaining characteristic of both plants which are to be grafted insures survival of both even if the grafting attempt is, for some reason, not successful. However odds of being successful are greatly enhanced because of the active growing condition of both plants involved and absence of a time limitation required for the healing of the graft union to occur before the dependent scion (top portion) dies from lack of sustenance.

The approach grafting procedure is as follows:

(1) Position a plant which will eventually become the rootstock (roots) as close to the desirable variety as possible. If plants are in containers, this can easily be accomplished and similar-sized stems (shoots) can be chosen to be united.

(2) From both plants closely position stems (shoots) which are at least three-eighths inch diameter and preferably close to the same size. At the point where the union is to occur, a slice of bark at least two inches long is peeled from both stems. The peeled area should be the same size on each.

(3) The two peeled surfaces are then bound tightly together with budding or electrical tape. Wrap completely with two complete covers around the area where the two peeled areas are in contact.

(4) Remove some of the top portion of the foliage from the desirable variety six to eight inches above the graft union. This will encourage a more rapid healing of the graft union.

(5) The union should be complete in four weeks. This type of grafting is most successful if performed during the growing season.

(6) After the parts are well united (4 weeks or more), the top portion of the rootstock can be cut off immediately above the graft union and the bottom portion or root system of the desirable plant can be cut off immediately below the graft union.

Images of this procedure can be seen at:

http://aggie-horticulture.tamu.edu/propagation/approachgraft/approach.html

(7) The graft union is now completed and the problems of iron chlorosis and indigenous soil pathogens have been solved if the proper rootstock has been used. Immediately after the portion of each plant is removed it may be necessary to reduce the leaf area of the top if wilting occurs because of lack of sufficient root system support. This situation will soon stabilize. If the only problem has been micronutrient (iron chlorosis)deficiency, the top, desirable variety will not need to be detached from its own root system--the approach grafted, adapted variety root system will "feed" the sickly plant what it needs. However, if the purpose of the graft is to control soil borne diseases, the susceptible variety should be detached from its root system and become totally dependent on the root system of the adapted variety.

Now that you know how to do the approach graft, what are the implications of such a graft? I have already explained how this graft can be used to correct iron deficiency and avoid soil pathogens but suppose that you want to grow a number of citrus trees but don't want to pay $40 for each and every tree. All you have to do is make more trees from your $40 tree by using the approach graft technique. Some nurseries sell citrus in containers such as Changsha tangerines and calamondins http://www.plantanswers.com/garden_column/feb05/1.htm
much cheaper than satsuma, lemon and grapefruit varieties. All you have to do is purchase some of the cheaper citrus types and do approach grafts to your more expensive citrus types. For more information about growing patio citrus, see:
http://aggie-horticulture.tamu.edu/PATIOCITRUS/

If you happen not to have the best of luck using the approach graft, the rootstock itself will produce an abundance of citrus fruit and fragrant blooms so this is a win-win situation. And the great thing about this grafting procedure is, "if at first you don't succeed, try, try again!" because both plants survive the technique.

This procedure also works well on grapes. Perhaps you had to move to a new home and you wanted to take a favorite grape vine with you. Simply go to your local nursery, purchase an adapted variety such as Champanel or Black Spanish growing in container, approach graft that favorite or heirloom grape, wait a month, make the described cuts and an exact duplicate of your favorite grape is ready to travel. In its new location it will be better than it was previously because it has a better root system. Or suppose that you already have a large Champanel or Black Spanish grape plant growing in your backyard and you would like to try some of the seedless grapes such as Flame or Black Monukka. Just go to your local nursery, purchase the variety or varieties which you want to try, position the containers in which the purchased plants are growing near similar size canes of the plants to be grafted onto and follow the outlined procedure. You can graft many varieties onto one large vine and enjoy many types of grapes over a longer period of time. Containerized nursery plants offer an endless opportunity to "manipulate" your plant into whatever you want to create!

One last possibility would be to put your favorite peach or plum on a Mexican plum rootstock.

Good luck and enjoy!!!