What in the world is a multi-fruit tree? It sounds like some strange type of tree you might find in Alice’s Wonderland, or in the forests of Oz . A tree that grows multiple types of fruit really is quite a magical thing to see! In this article, I’lll explain to you how you can cultivate this kind of biological magic in your own garden.
A Multi-Fruit Tree is All About Grafting
What we’re really talking about here is the art of grafting. This is a technique that involves permanently connecting a bud or a shoot from one plant onto the root or trunk of another. A successful grafting can make your plum tree grow peaches and apricots, or give your grapefruit tree a lemon section.
Being a ‘Tree Doctor’
Grafting is basically a type of tree surgery, in which we are the doctors. During this procedure, the living tissue of two separate species are connected forever. This might sound beyond your range of gardening experience, but trust me: it’s not as complicated as it sounds.
One important thing to remember is that this technique requires you to be attentive to your plant’s needs. Like a surgeon, you’re slicing away the tree’s protective bark layer and exposing its tender insides. Take special care here so you don’t allow bacteria and pests into this vulnerable area.
Like any good surgeon, you’ll want to use a clean, sharp knife. Choose a knife that has a flat edge on one side of the blade (unlike kitchen knives that are beveled.) The flat edge will help to make a much cleaner, straighter cut that will heal together much faster. Remember: the surgery itself may only take a few minutes, but the wound will take several weeks to heal.
The living tree that you choose to graft onto is called the “stock”. Any cutting that you surgically attach onto this is called the “scion”. For a successful grafting, you’ll want your stock and scion to be similar plant species. Quite simply, a pear can’t be grafted onto a lemon tree, and an apple can’t be grafted onto a pear… but, a crabapple can be grafted onto a Honeycrisp apple tree.
(This combination won’t just produce both types of apples—it’ll create a self-pollinating tree!)
Trees in the Prunus family are usually compatible with each other as well. This family includes: peaches, plums, almonds, apricots and nectarines.
Many combinations of these trees can be grafted together, though a little research should be done beforehand to ensure their compatibility. Some plum types can’t be grafted onto certain peaches or nectarines, for example. Similarly, trying to attach an almond scion onto a plum requires a separate step that standard grafting does not, etc.
If you’re trying to graft onto a citrus tree, you’re in luck! Most citrus fruit trees are compatible for grafting with other citrus fruits. It’s entirely possible to have a single tree that grows lemons, limes, tangerines, grapefruits and oranges. These trees are commonly called “citrus cocktail trees”, or “fruit salad trees”.
The best time to attempt grafting is in the coldest part of winter, usually from January through to March. This is prime time because the scion wood is dormant. If you collect scion wood in the early parts of winter, you should be able to find some healthy shoots from the previous season growth’s that are dormant.
Note: if you aren’t able to collect your scion wood in time, you can still purchase scions online.
The scion should be 6-12 inches long and have three to four buds on it. It should also be about the same diameter as your root stock. When you make your cut, make sure to cut above a bud. If you need a bit of extra time before getting to work, keep your scion cutting dormant by storing it in a fridge inside a zippered plastic bag. Add a few drops of water into the bag to help keep it happier longer.
The most important part about selecting rootstock, as mentioned before, is that it must be compatible for grafting with your selected scion. It’s also important that you find a part to graft that is as close to the same size as your scion as possible.
If you’re looking to buy a new rootstock, be sure to check out varieties that are resistant to diseases and pests. Another good thing to consider is the average temperature in your area. and whether or not you’ll want to get a variety that can withstand a bit more cold temperatures. Checking with your local extension office will help you find out what type of rootstocks in your area will work best with the scion you’re wanting to graft with.
“Whip and Tongue” Grafting
There are several different grafting methods, but one of the most common—and effective—types is called “bench grafting”. Actually, this is more commonly known as “whip and tongue” grafting. This is incredibly effective because the extra surface area of the “tongue” helps the graft to create a much stronger union.
If you’d like to try this grafting method, choose a smaller scion and rootstock. Choosing those with 1/4- to 1/2-inch diameter is just about perfect.
When making your cut, keep the flat edge of your knife downwards. Make slanted cuts on both your rootstock and the scion, and do your best to match up the angles on both so they fit together nicely. It may take a few tries, but it’s important to get the best fit you possibly can, here.
Next, create the “tongues” that will help the rootstock and scion make a good connection. Very carefully slice a small sliver on both freshly cut surfaces. By doing so, you’ll create a small tongue that just barely sticks off from the rest of your wood. These tongues only need to be about a 1/4 of an inch deep. They’ll interlock when the scion and rootstock are finally joined.
Remember to be fastidiously clean during this part so as not to introduce contaminants into your graft.
There are many informative videos about grafting online. Since this is an actual tree surgery you’re attempting here, watching videos such as the ones posted above and below will help you more firmly grasp this concept. Furthermore, it’ll help your chances of creating a successful and healthy graft.
Connecting your Graft
The cambium layer is the green layer of woody tissue between the wood and the bark. It’s essential that this layer has good contact when connecting your rootstock and scion! If the rootstock and scion are different sizes, try to match up as much of the cambium layer as you can. As you connect the two pieces of wood, make sure to gently interlock the two tongues so they fit together firmly.
Wrapping your Graft
After connecting the two pieces of wood, you’ll need to wrap them with grafting tape or wide rubber bands. A lot of folks prefer to use wide rubber bands instead of tape, as they create equal pressure from all angles and are easy to unwind afterward.
Rubber bands will also help to keep air out, and won’t pull off the bark as tape would. If you use a rubber band, start winding up from the bottom and tuck the end into the final loop.
Tie a small splint on the outside of the rubber band/grafting tape if you feel it needs additional support. This is a smart option if you happen to live in a windy area.
Caring for Your New Multi-Fruit Tree Graft
If you live in a region where the ground freezes, you can either keep your grafted tree inside for the winter, or wait to graft until the ground thaws out. If you decide to wait until after winter to graft, you’ll want to do it as soon as you’re able to in the very early springtime.
There’s a pretty good chance that your rootstock will start shooting up suckers during the first year. Remove these as soon as you see them, as they’ll take away energy from your graft.
If everything goes well, you should start seeing new growth within a few weeks. Keep your newly grafted tree well-watered for the first year. Water weekly, if you can. Within about 3 years, all your hard work will pay off and your grafted tree should be strong enough to begin producing fruit.
There are three other types of grafting that you might want to research: cleft grafting, side veneer grafting, and bark grafting. They might be worth your time to check out, if for no other reason than to learn more about your plants and trees and how they grow.
By following this guide, you should be able to grow several types of fruit on a single tree. This is a great option if you have limited space, but want to grow a variety of species to enjoy.