What is a tipping level and what does it mean to tip canes?

It means just what it sounds like - you cut off the tip of the new growth on
last year's canes (branches) to encourage more growth of lateral branches, and
more fruit. If you let the canes remain too long, they will just bend over from
the weight of the growth on the ends, making it harder to get at the fruit.
IMHO, after the leaves come off, and before spring growth starts, you need to
remove any branches that have borne fruit the prior year, leaving the new
growth from the ground the prior year. (Fruit come from branches off canes in
their second year - the prior year's new sprouts from the ground) You should
cut the second-year canes to a manageable height, and "tip" them again in the
spring when growth resumes, for the reasons I already stated.

Most varieties of raspberries grow like weeds, and benefit from the pruning. I
just cut back a lot of this years growth (next years fruiting canes) because my
bed was begining to resemble a rain forest - with thorns. The stuff that bore
fruit a few month's ago will not grow much at all, and, since it will die for
good with the fall, I'll leave it alone until then, when I will cut it all off
to make more room for the coming fruit next spring....


-=epm=-

In matters of truth and justice,
there is no difference between large and small problems,
for issues concerning the treatment of people are all the same.
- Albert Einstein