I live in nothern California in the San Francisco/Oakland bay area and was wondering if this was a good time to prune my Japanese maples. I keep getting conflicting information, so i thoought I'd ask you folks who have given me great info in the past. Thanks.
Might bleed a little, done during cold weather. Otherwise, the best time to prune it is after you learn how. What are you planning to do?
I have learned how to prune the trees, it's the timing I'm not sure about and have gotten conflicting advice. I usually prune when there are leaves on the trees. However it's a lot easier for me to prune when there are no leaves like it is now, but a couple of years ago I did some pruning in late January, early February and one tree did bleed. i was wanting to thin them out a bit.
Here is an article by Nancy Friars on pruning for the winter silouette which might be helpful http://www.mountainmaples.com/WS4D_Cookie=1.13.07_02,57,48_19/article2.html
Hi I pruning in feb /mar for ligth prune and january for heavy prune I read this method some years ago an article by Giordano Girardelli on "Gardenia" N°210 A.
Not sure what the climate is like where Alex is, but I think the issue in the SF bay area is that it never gets very cold (compared to most of us); especially in SF and Oakland. Wonderful climate in Oakland... Personally I think this is an OK time in your area.
Hold on a couple weeks before it turns a little warmer if it is not a great deal for you. I pruned two JMs a week ago, they are still bleeding and attracting a lot of ants around the wounds (because of sugar) - not a very pleasant picture. I think we share the same/similar weather.
Ok I read in "Maple of the World "appendix 6 S.Lorenzo is zone 9, I live near Rome and Rome is zone 9, A.
I like to prune early spring when the buds begin to swell. If you prune to early you will will be more likely to get botrytis in the tips of the wood. Summer is also a good time to prune.
This is an interesting topic since it seems that there are several conflicting views. I'd like to invite the experienced people to fetch in. I guess everybody agrees that (japanese?) maples bleed heavily when cut no matter the time of the year, does everybody agree on this? I have found myself that they indeed bleed no matter when I prune them, however I cannot tell if it is more in one season than the others. If this is true, then the theory goes that it is better to prune when the tree can react and heal the wound promptly. Thus the advise to prune in early spring. But it should also apply to anytime during the growing period (as Yweride points out), or, are maples capable of healing better in early spring? Let's hear from others Gomero
Hi I have had good result whit A. rubrum in autum after the leaves down ,this maple not bleed,I look that some maple bleed much if cut ater have fertlizer . A.
Interesting, Gomero, that your maples react in a different fashion than mine. My JM never bleed much - I have pruned at various moments of the year. My acer saccharum Borcade however is a different matter: I have pruned it in February and it has bled massively for a couple of days, in early January not at all. It has been suggested to me to prune in August, which gives the maple time to close the wound before winter.
What do the books say?, of those in my personal library I can extract: Vertrees says "....major pruning should be done during the dormant season from late November to early January, well before the sap starts rising......", "....corrective pruning can be done any time of the year except when the sap is rising..." James Harris (in 'The Gardener's Guide to Growing Maples') says :" Pruning is best carried out when the sap is falling in late Summer and early Autumn, light pruning can be carried out in the Spring" Sunset Pruning Handbook: " Avoid pruning is Spring just before and during time of active growth: most bleed sap profusely then" America Horticultural Society Pruning & Training Handbook: "Prune in Winter when fully dormant: maples bleed sap profusely at other times. Small cuts may safely be made in late summer/early autumn" George Brown (in The Pruning of Trees, Shrubs and Conifers) says: "....carry out any pruning which is necessary in the late summer or early autumn" This book has the best content on pruning maples, analyzing section by section. Well, as you can see there are varying opinions on when is best to prune!!! Please complete if you have other references. I have joined the Maple Society just recently, I was wondering if the subject of pruning has been addressed in past issues of the booklet. Gomero
So, nobody else wants to pitch in.;-) I add another quotation from a book I bought recently: Peter Adams' "BONSAI with Japanese Maples". He advises "......structural and heavy pruning is best done in August, trees are at a plateau in their growth ......and there is enough time for some healing before the frosts arrive...and seal all the cuts" The conclusion that can be drawn from all of these expert's opinions is that there is no consensus on when is the best time to prune Japanese Maples. There is consensus on not to prune in early Spring. Daniel, this thread probably deserves to be stickied since when to prune is a very common question that comes up often. Gomero
Thanks for that Gomero, as I hadn't read this thread before Personally I will prune lightly at any time of year and have always done so without any ill effects More major pruning I will leave until after leaf fall in autumn. This is mainly because the sap is no longer rising, and it is much easier to see what pruning is necessary when there are no leaves on the tree I have never thought about pruning in Spring because the need will simply not occur when I have dealt with the tree already In Northern Ireland I have seldom had much bleed from pruning cuts
Hi, a week ago, I pruned my two green JM due to burning leaves and to do some shape. I made a heavy pruning and actually the JMs are performing very well and some branches already have new small leaves. I didn't see mayor bleeding when cut them. However, when I need to prune, I try to follow an old advice from my mother and my grandfather (during his wole life he managed his own farm including an orchand an he cultivated with a lot of fruit trees). He stated that the moon affects nature and all living things. No matter the plant or the season involved; the correct time for prunning and planting must be performed according to the moon phases. It could sound crazy, but he said that if the moon has the power to affect the oceans, seas and rivers with tides; so in the same way it affects the fluids in any living thing: he said that during the light (waxing) of the Moon, sap is thought to flow more strongly, filling plants with vitality and energy, favoring the planting and harvesting of crops that mature above ground. He, as my mother follow strict time to avoid prunning: never during waxing of the moon due the fact that the healing process and grow will take more time, and also the plant will have more bleeding. As the moon wanes during the 3rd and 4th quarters, it said that this is a good time to prune plants, as the water table is diminishing and so less sap will flow out of the cut ends. The plants are said to orient themselves toward their roots, making this a favorable time for planting, transplanting and harvesting root crops in general. The 4th quarter is the most dormant period and is good for chores like weeding. I don’t know if all of this is really true, but for me, to follow this advice is very cheap (for free) and won’t have any adverse effects in the plant so could be worthy to give a try. Nelson
yes see moon phases in garden is a good method ;i use this for hortoculture not for prunned maple !year that you use this method?
"There is consensus on not to prune in early Spring." I've been around these plants a while now and do most all of my pruning in the early Spring. I am not so sure that anyone that states this time of the year is not a good time to prune, in USDA zones of 8-10, really are not all that familiar with these zones at all. I regard any attempt to state that early Spring pruning of Japanese Maples is not a good time for these plants in zones 8-10 as being suspect. One thing we have to keep in mind, one that some members of other UBC sub-forums do not fully know or understand yet is that what may or may not work for Fruit, Nut and Pome trees may or may not be good practice for pruning other trees. We cannot always equate what will be good practice for pruning Ornamental trees and when to prune them will be solid advice for pruning the palmatum type Maples. Shoot, it is suspect methodology to equate pruning all Acers in the same fashion and at the same time of the year. I wouldn't prune Silver, Sugar and Norway Maple the same way or at the same exact time as I will the palmatum type Maples. As a matter of fact I don't even prune the Japonicum, Sieboldianum and Shirasawanum at the same stage of Spring development as I will the palmatum type plants. Some areas can get by pruning in August but in some areas this practice may not be all that beneficial to the plant. Here, with us having late new growth up until December with non-Fall color leaves in mid December or latter sometimes, like this year, on some of the palmatum type plants, it may be a mistake to hard prune in August. April, May and no later than early June may be more acceptable, even in January for a hard prune but around here with some Maples leafing out in early February the best time for me to prune is either soon after the Spring leaf out before the next flush of new growth or right after the first flush of new growth before onset of the second flush of new growth by mid March for most of our palmatums. As JT1 wrote in a recent thread this timing gives us plenty of meantime to see new growth emanate from areas where we hoped we would see new shoot development. Even with horizontal cuts we can see new bud formation form right below our cut around here, whereas in several areas a horizontal cut on a Fruit tree is frowned upon but rather angled vertical cuts are more preferred. Not only may our timing be different to prune palmatum type Maples from other plants but our technique may be different as well. I saw a marvelous specimen dissectum hand pruned by Mario in a Fall color thread. I suggest a few book authors ask him what all he did, when he did it and what was he wanting from this tree before he ever pruned it. I have an idea to what those answers are and can see for myself what hands on care can do for a tree that others would not dare prune due to their misconceptions of how and what these trees do, depending on where they are located. In cooler climates say USDA zones 4-7 Winter pruning may be advisable but it does help to know what we can expect from soft wood or hard wood prunes from people that have done it for containerized trees and in ground and not from people that want you to believe they have actually pruned palmatum type trees. Also keep in mind that what may work well for bonsai specialists may not work too well for palmatum type trees in ground and I'll take it further by stating that bonsai techniques may not be advantageous to juvenile and older containerized palmatums. Standard bonsai practice of pruning roots for pot bound and root bound container trees may be necessary but to uproot a tree that has been in the ground a while just to prune the roots could be disastrous for us, especially around here. We may read of a success story every now and then but we seldom read of the number of plants that died out due in large part to our overzealousness and in some cases due to lack of credible and working knowledge of the plant in question. Jim
Good addition to the thread Jim. It makes a lot of sense to remind readers that they should carefully assess their local climate vs. plant behavior. Following your comments I may rephrase the consensus by saying you should not prune when the the maple is actively leafing out (1st, 2nd or, like in Houston, 3rd flush). Gomero
When we analyze what others state in theory of what is a good time to prune, we need to be more qualitative (when) and quantitative (what, either soft wood or hard wood). I have been just as guilty with oversight and perhaps assumed too much sometimes with some of my posts in this forum, giving the impression that what may work across the board for other similar trees or plants will work for our tree. The one constant is that we can prune soft wood most any time of the year for the palmatum type Maples (Acer palmatum, Acer amoenum, Acer matsumurae). The tricky part and one area that can be quite different for us, depending on the cultivar, our location, time of the year and why are we wanting to prune in the first place, is when to prune hard wood. I'd be quite interested to read of any palmatum type cultivar that tends to bleed after a pruning. The reason why is we never see a palmatum type plant bleed here. no matter when we prune it. Bleeding can be an issue with other Maples however, much like an English Walnut or Pistachio can act when they are pruned at the wrong time as they can bleed sap quite freely. I prefer the Sunset Western Garden Book zones rather than the USDA zones as the former zonal denotations tend to take microclimates more into consideration than the USDA zones will. We may be in the same USDA zone as let's say Atlanta, Georgia but although there are some similarities in both of our locations for degree days without freezing temperatures, there are definite dissimilarities as well in heat flux and transpirational water loss. During the Summer, both locations may be warm to hot but one area is humid and the other certainly is not that, We are a pronounced dry heat here with very low humidity. Thus our plants respire more and we have more transpirational loss as a consequence, which is one reason why we see more leaf burn, leaf margin burn than the more humid zone generally sees on their trees. Can just when a potential leaf burn determine when we may want to prune our trees? Yes, it can and our WGB zones 8 and 9 around here can serve as a good testament. We can prune hard wood most any time of the year if we are wanting disease suppression from the likes of Tight Bark and internal Verticiliium alboatrum but we do not prune hard wood year round just because we feel like it. There can be some dramatic drawbacks to the palmatum type tree depending on where we are growing the plant. Jim
Thank you for this information. It is very helpful since I am planting to prune my JM's in the future. I think I am waiting till late Autumn to do that.