Eucs, in general, are much faster growing than most other trees in cultivation.  Most euc species can be expected to achieve 6 - 12 feet of new growth each year.  Exceptions include some of the snow gums (E. pauciflora and its subspecies, E. gregsoniana, etc.), which usually take a couple years to establish, during which they may only grow a foot or two each year; and a few other unique species such as E. vernicosa, E. stricta, etc. which are quite slow growing.  (These exceptions are all noted in the euc species index.)  But even many of the snow gums will pick up to 4 - 6 feet per year once they are well established.

So, if you have planted a large or rootbound euc, and you are pleased that it has grown 3' in one year, you should not be (in the opinion of this euc grower).  Because if you had planted a small one, it would grow much faster.  3' per year may be an acceptible growth rate for many ornamental trees, but for most euc species it is quite pathetic.

First, eucs have it much easier in cultivation than they do in their natural habitat in Australia.  In cultivation they are not tormented by grazing kangaroos, koalas, and all sorts of insect pests.  In addition, most gardens and landscapes offer good soil, and freedom from competition with grass and other trees - neither of which they usually get in their homeland.

Second, eucs do not "harden off" or "go dormant" in the way we usually think of trees preparing for the winter.  They are able to grow whenever they have access to water and a little warmth, regardless of what time of the year it is.  This is quite different from the regime of most other trees, which do most or all of their growing in the spring and early summer, and then stop.  In addition, if they do stop growing for any reason (whether it be summer drought or winter cold), they do not require a certain "resting period" or period of dormancy before they will resume growth again.

The other factor, besides being potbound, that can cause eucs to grow much more slowly than they might, is competition from grass and weeds in the garden.  If a euc is planted in a pasture or lawn with grass growing right up to the base of the tree, it will grow much more slowly than in good garden conditions.  However, they are able to recover from this condition much more quickly than from being rootbound or overgrown in a pot, if the problem is corrected.  A good heavy mulch around the base of the tree will help immensely.

First, planting them small avoids the problem of their growth rate being stunted.  Eucs are unique among trees in that they take many years to recover from being rootbound in a pot, or being planted too large!  In some cases, they may never recover.  Normal trees may take a year or two to recover from being rootbound, but for eucs the problem is greatly amplified.  Although I cannot explain why this is so based on the technical physiology of eucs, I have learned over the years to have nothing to do with large or rootbound eucs.  (Some subtropical and tropical species are exceptions, and are better able to recover than the hardy species covered on this page.)  Generally, though, eucs should not be grown by the conventional manner for other landscape trees.

Second, large plants with not enough root mass are often unstable and liable to blow over in a windstorm.  This problem is often difficult to correct except by cutting the tree back to reduce its top-heaviness, in which case you might as well have planted a small one.  Staking to correct this seldom works, since it causes the development of a weak trunk - in fact, staking is often largely the culprit for trees that blow down.  (There are certain ways that staking can be used, as mentioned elsewhere on this page.)
 

My experience with large and potbound eucs is limited, since it did not take me too many tries to figure out that potbound eucs are really not worthwhile at all.  However I have done some fairly controlled experiments with E. dalrympleana (and a couple other species).

In June 1996 I planted a Eucalyptus dalrympleana (let us call it "Tree A").  At the time, it was 28" tall, and rootbound in a 1-gallon pot.  By September 1998, it was still only about 5 feet tall.  Then in December 1998 it froze to the ground.

In August 1997 I planted another E. dalrympleana ("Tree B") out of a 4" pot - it was only about 10" tall.  It grew to about 28" by that winter, and then proceeded to grow to about 13 feet by December 1998.  Sadly, it also froze - even though it was much larger than the other tree, it was still not quite large enough to make it.

So, to chart the growth rates of these trees:
 

Tree A has now grown back from the base and since I have taken very good care of it over the last couple of years, it appears to be on its way to making 7 or 8 feet of growth this year - still not as fast as it should, but it may make a nice tree yet.  Tree B did not grow back after the freeze.  I believe it may have been a rather cold-tender provenance to begin with, since the juvenile leaves looked an awful lot like those of E. viminalis.
 

The picture at left (sorry for the poor photo quality) is Tree A in September 1998.  (I did not get any pictures of this tree when it was younger.)  The picture at right is the same tree in July 2001.  Even though it has had 2&1/2 years now to grow back after freezing to the ground, it is still not all that big (about 8' tall).  But it is doing much better than it did in its "first life." The left picture is Tree B in December 1997.  In the right picture, the left tree is Tree B in September 1998.  It is about 10' tall in this picture and grew a few more feet before it froze that winter.  (The other two trees at right are E. viminalis, which froze, and E. parvula, which was not damaged.)

In July 1999 I planted several more E. dalrympleana as small plants from 4" pots.  Since then, they also have produced similar results to Tree B, putting on over 10' of growth in one year.  After just two years they are about twice as tall as Tree A.

I could relate similar experiences with E. coccifera and E. perriniana.

I have also had problems with large planted eucs and wind.  I did have several eucs (E. bridgesiana, E. regnans and E. perriniana) that were in large pots and a bit top heavy, but at the time I did not think they were completely irrredeemable, so I planted them.  They were in the ground for a couple years, and eventually seemed to recover somewhat (though not entirely) from having been large-planted - by summer 1998 they were making fairly substantial growth, but still not as much as a small-planted plant could have produced.  Just when I was getting optomistic that their recovery may have been worth the wait after all, several moderate windstorms with gusts of about 50 mph blew them over in November 1998.  The E. regnans, in fact, was so unstable that it was ripped completely out of the ground and deposited several feet away, trunk and all.

It was then obvious to me that because they were planted large, they failed to develop the strong root systems that they would have if they had been planted smaller.  (The E. bridgesiana actually recovered, after freezing to the ground that December, and is now quite a sturdy tree after having to start over.)

Bruce Ritter is the owner of Northern Tropics Nursery in Mt. Sinai, New York.  He had been keeping his eucs in pots, in order to grow them to a large size before planting them out.  I suggested that he try planting them at a smaller size and watching how fast they grow.  He writes:
 

A couple months later, Bruce writes:
 

Sadly, this Eucalyptus camphora, as well as most of the other species he was growing, were severely damaged by cold temperatures the following winter.  He needs hardier seed provenances!  Also, his plan with the E. debeuzevillei might have been slightly disappointing since it is a snow gum and does not grow quite so fast as most other euc species.

Eucalyptus Nurseries Ltd. is a grower of eucs in Wales with more than 17 years of experience in the business.  They have stated some truths about this subject so eloquently, that they are very much worth quoting here.
 

When selecting a euc to purchase, look for the following desirable traits:

• The plant should be fairly small - as a general rule, about 6 - 10" tall for a 4" pot (depending on the depth of the pot), a 12 - 16" for a 1 - gallon plant, and no taller than 2' for a two gallon plant.
• The plant should be sturdy if it is in a two-gallon pot.  Smaller plants under 1' tall may not appear very sturdy, but will acquire sturdiness once planted out.
• There should be no evidence of the euc's growth rate having been slowed down from being in its pot - for example, if the new growth appears somewhat congested.
• The plant should appear healthy and vigorous.

Here are two eucs in 1-gallon pots that would be suitable for planting out.  The one on the left (E. neglecta) is slightly on the small side and will have no setback of the growth if planted now.  The one on the right (E. glaucescens) is slightly larger than would be ideal and will be set back just a little, but is still not too unsuitable for planting.  Both are generally healthy and vigorous. Here are two eucs in deep 4" pots, E. dalrympleana (left) and E. nicholii (right).  Both of these are very healthy and ready to go in the ground.  If planted now, they will be very well-established in a matter of weeks.  (In fact, since I planted that E. nicholii in my garden just after taking this picture, I can personally attest to this!)

Avoid purchasing eucs that show any of the following problems:

• A top-heavy euc
• A euc with a weak trunk that is not sturdy at the base
• A euc with a stake closely tied to the trunk
• A euc that is out of proportion with the size of its pot (see dimensions listed above) - especially very tall eucs in 5, 7 and 10 gallon pots.  (For example, in the Pacific Northwest, tall E. cinerea are frequently sold in 5 gallon pots, and tall E. pauciflora ssp. niphophila and E. gunnii are sometimes seen for sale in 7 and 10 gallon pots.)
• A euc with congested new growth, or growth that looks like it may have been slowed down from being in a pot
• A euc with circling roots at the bottom of the pot, or any other matted entanglement of roots
• A euc with roots growing out of the pot (although for some deep pots with large openings in the bottom, this is inevitable and can be excused)

Here are two eucs, both E. parvula, that have grown too large for their pots and should not be used.  The tree at left is in a two gallon pot, but has grown to at least 3' tall.  Even though it appears to be healthy now, it is probably quite rootbound and its growth will still be slowed significantly.  The tree at right is certainly very rootbound - fortunately the nursery is using it strictly as a display specimen rather than trying to sell it.

If you do get a euc that falls short of these desirable traits (in the first list), it is not necessarily destined to fail.  Information about how to correct these problems continues under Cultural information for growing Eucalyptus in cool climates.

Finally, remember to plant it immediately after purchase (at least within a few days).  They grow so fast that leaving it in the same pot for even a couple extra weeks can greatly effect how rootbound it becomes, and how vigorous it is when planted out.

Small trees have the disadvantage of not providing as much of an instant effect in the garden as a larger tree.  In addition, they are not sufficiently ignoramus-proof in commercial landscapes.  Trees that are not fairly large to begin with run the risk of being trampled, sprayed (by someone who thinks it's a weed), or severely pruned (by someone who thinks it's supposed to be a shrub).  Since customers often demand larger specimen trees, it is certainly worthwhile to find ways to grow larger trees that will still be suitable for planting.  This will also allow their planting in more public places, once contractors catch on.

In spite of all my dire warnings against planting large potted trees, more recent evidence would suggest that there are ways to make it successful.  Trees that are grown to several feet tall in large pots, and that have sturdy trunks (i.e. not staked), may still make successful trees without much of a growth check.  (The large E. glaucescens at Steamboat Island Nursery, pictured here, was grown by this method.)  Most importantly, the top growth must not be out of proportion with the root mass.  Regardless of the size of the rootball, it must still contain a great many roots throughout; they cannot all just circle at the bottom.  One possible way to achieve this in the nursery would be to withhold nitrogen and fertilize more with potassium, phosphorus and micronutrients.  The consistency of the soil media should also be designed for maximum root density.
 

Of course, most large eucs commonly found in nurseries are still unsuitable, either because the size of their root system is not sufficient to support the top growth, or because the trees have been staked and are weak and unstable.  I would still urge the buyer (and the nurseryman) to be very cautious about this.