Start a tree from nuts* or acorns? The idea may seem far-fetched to beginning gardeners. After all, won’t these nuts take years before producing good-sized trees? But as you gain experience gardening, you’ll find that you’ll learn to be patient … and you’ll discover that young trees actually grow faster than you’d think. When I look at some of the trees I’ve sown over the years and how they now dominate the landscape, I’m actually proud I put my trust in them!
*For simplicity’s sake, in this text, I’ll be using the word “nut” to describe any large seed with a hard shell, not in the strict botanical sense
Besides, sowing trees will save you a fortune! If you know where to look (parks and arboretums, for example), you can harvest nuts at no cost whatsoever, even of the rarest species. Free trees! Who would have thought?
Most nuts from temperate climates need a lengthy cold stratification before they will germinate, that is, several months in cool to cold, moist conditions. In the wild, they drop to the ground in fall and, after a cold winter that softens their hard exterior, germinate the following spring. So just do like Mother Nature and sow your nuts in the fall!
Nut trees depend on largely on squirrels and a few other allies (chipmunks, jays, etc.) to distribute their seeds. Nuts are just too heavy to travel far on their own and, without squirrels and their friends, they’d mostly germinate near the mother tree. Squirrels, on the other hand, will carry nuts long distances from the original tree, then conveniently plant them in the ground at just the right depth. Of course, squirrels do so to store food for future use, but then often forget them. This successful symbiotic relationship has in fact been going on for millions of years.
But squirrels won’t necessarily be planting the nut tree you want to grow exactly where you want it to be. Of course, you could try digging up squirrel-planted tree seedlings in the spring, but most nut trees produce a fragile taproot that makes them transplanting them difficult if you don’t do it immediately after germination. That’s why the easiest way to grow nut trees is to be like a squirrel and sow them yourself.
Harvest and Preparation
Typically, nuts fall from trees when they’re ripe: usually between September and mid-November in the Northern Hemisphere. It’s no coincidence that this is also the best time to sow them.
Collect fallen nuts and examine them, eliminating those that are cracked or pierced and keeping only those that are intact.
Soak the nuts in a container of water for about 24 hours. Those that float are sterile and can be rejected; those that are viable will sink to the bottom and are the ones you should plant.
You will notice that the hulls of most nuts—chestnuts, hickories, beechnuts, etc.—split open at maturity and release the nut inside, but that’s not the case with walnuts (Juglans) and hazelnuts (Corylus). You can plant them whole, but germination is better when you shell them beforehand. Put on waterproof gloves, however, before shelling walnuts, otherwise they’ll stain your fingers.
You don’t have to remove the cup from acorns, but if it comes off on its own (whether it comes off or not depends on the species), that makes no difference.
In the fall before the ground freezes, sow nuts where you want them to grow. Obviously, the conditions have to be suitable for the chosen species, so make sure you take into consideration soil type, drainage, exposure, hardiness zone, etc.
Prepare a planting hole about three times deeper than the nut is high and drop in 3 or 4 nuts (it’s always wise to sow more than you need in case germination is low). If soil in the sector has been severely disturbed, it may be useful to sprinkle mycorrhizal fungi (beneficial fungi) on the nuts. Fill in the hole with soil and water well.
To prevent squirrels from stealing your nuts (and they will dig them up if you do nothing!), place a 1 foot by 1 foot (30 cm x 30 cm) piece of chicken wire (wire mesh) over the planting site and stake it solidly to the ground. Cover the planting with about 3 inches (7.5 cm) of mulch to moderate the effect of winter temperature fluctuations. Next, go back indoors and warm up!
When young trees sprout in spring, remove the chicken wire, then thin your planting, removing all but one seedling per spot. And that’s all. Who thought that planting a tree could be so easy?
Seedlings generally grow rapidly during the early years. By the age of only 5 to 7, they’ll have become presentable trees … at an unbeatable price!
From my perspective as a laidback gardener, the easiest way to plant a tree is to sow it where you want it to grow, but some gardeners prefer starting their seedlings in pots. That involves extra steps, but is still a viable option. If that’s your choice, remember that you’ll still need to give most nuts a lengthy period of cold stratification.
Just sow the nuts as above, but in pots. Place the pot on the ground in a protected spot and cover it with poultry netting and mulch. They’ll sprout in spring. Simple!
Or, seal the pot in a plastic bag (to keep the potting soil moist) and put the pot in a cold but frost-free place indoors, such as a cold cellar, a refrigerator or a barely heated garage, and leave it there for two to three months. When you expose the pot to the heat and light in the spring, the nuts will quickly germinate.
Some gardeners prefer skipping potting up entirely and simply drop nuts into a plastic bag filled with barely moist sand, the place the bag in the cold for two to three months. They then move the bags to a warm, moderately lit spot until germination.
When the nuts do sprout, just transplant the seedlings in their final spot. It is best to do so fairly quickly, while their roots are still quite short. If the roots start to become confined in their containers, and that can happen quickly, this can stunt the tree’s growth for years to come.
Trees: so easy to grow from seed that one wonders why gardeners don’t do start them that way more often!