I bought a dwarf Alberta spruce at a nursery. An employee said that conifers can be pruned any time of the year. I'm not sure if he was totally correct. Would pruning cause a shock during the growing season? If I were to prune it during this growing season, would I need to keep it in the shade for some time?

I have never heard that before. Maybe you can, maybe it survives. But for sure not the best time. I have done das pruning from late authum to early spring and it seems to work good for me no matter.

Why do you want to prune now?

Tropfrog wrote:

I have never heard that before. Maybe you can, maybe it survives. But for sure not the best time. I have done das pruning from late authum to early spring and it seems to work good for me no matter.

Why do you want to prune now?

To prevent overgrowth. You have never heard what before?

Many employees at that nursery would say similar things. I could prune it now or any time of the year. Their reason was because gardeners prune trees all year round and a dwarf Alberta spruce was not an exception from being a tree.

I still don’t know though. Could I prune it without repotting?

Never prune and repot at the same time.

Strong pruning of picea is best done late summer early fall. Maintenance pruning is done in spring, before the young growth turns mature.

After strong pruning for most species it is best to shade them a little as parts of the plant become exposed to the sun that were not before and therefor there is a risk of sunburn.

leatherback wrote:

Strong pruning of picea is best done late summer early fall. Maintenance pruning is done in spring, before the young growth turns mature.

After strong pruning for most species it is best to shade them a little as parts of the plant become exposed to the sun that were not before and therefor there is a risk of sunburn.

When exactly is late summer/early fall? In California hot temperatures persist through September and temperatures won’t start dropping until October. But with climate change fall is a very short period and doesn’t start later into the year. In fact deciduous trees didn’t start losing their leaves until December [2020] last season.

Interesting question indeed and a challenge for an international forum. . I use the swedish metrological institute to tell me what season it is. They define authum as when average day temperature has been below 10c for 7 days in a row. So late summer would be at any time it has fall below 10 just a few days. But looking at when trees start to change colour might be good hint as well.

Check out bone dry bonsai on Youtube. He is in california and can be a good hint on when to do things.

Wheels the advice column says do,something in the fall or spring it really means do it when the tree thinks it is fall or spring, not when a calendar entry picks up. Some of my trees leaf out in February, some in March, and some in April. I pot them when the buds start to swell, not a calendar time.

It would really be more convenient to mark a calendar time, but it is the tree, and they don't know how to read the calendar.

Fall is harder to define. Some deciduous trees change leaf colors in late October, some in early December. In this climate I don’t have to winterize much so I don't have to do much, and that is more a response to weather forecasts. We joke about going out of town for a weekend and missing winter because we usually get no more than a few days of serious frost.

Last year it was below freezing six nights, most of the just a few degrees and only two nights of hard freeze, 19 to 24 F/-7 to -5. Winter is hard to define.

Ivan wrote:

Wheels the advice column says do,something in the fall or spring it really means do it when the tree thinks it is fall or spring, not when a calendar entry picks up. Some of my trees leaf out in February, some in March, and some in April. I pot them when the buds start to swell, not a calendar time.

It would really be more convenient to mark a calendar time, but it is the tree, and they don't know how to read the calendar.

Fall is harder to define. Some deciduous trees change leaf colors in late October, some in early December. In this climate I don’t have to winterize much so I don't have to do much, and that is more a response to weather forecasts. We joke about going out of town for a weekend and missing winter because we usually get no more than a few days of serious frost.

Last year it was below freezing six nights, most of the just a few degrees and only two nights of hard freeze, 19 to 24 F/-7 to -5. Winter is hard to define.

But how can you tell if a conifer, particularly spruce, is sensing a fall season?

Wes wrote:

But how can you tell if a conifer, particularly spruce, is sensing a fall season?

At the moment the only conifer I have is a bald cypress. I have killed junipers, dwarf Alberta spruce, pines, and others. Maybe I should tell how they sense fall a little better.