Q. I live in Northridge, CA and have Rosenkas (a variety of
Bougainvillea that is used as a ground-cover) that are 2 years old. They have almost no
bracts on them, and very long branches (over 4 feet long). They are
planted in the ground - not in containers, 2 feet apart and were planted as a
ground cover. They are hand watered; no more than once a week. I
haven't used any fertilizer, but have amended the soil with homemade
compost. Maybe the compost contains too much nitrogen? The
plants do get more than 1/2 day of sunlight. Could you let me know
approx. how many inches should be cut off the branches when I prune them in
spring? Some are close to 72" long.
What is the best fertilizer to use and during
what season should this be applied? Also, at what time of the year
should they be pruned?
A. The following things will cause bougainvilleas to favor
vegetative growth over producing bracts and flowers:
1.
Too much nitrogen. I have never seen a bougainvillea in need of
fertilization.
2.
Too much water. They should be watered no more than once a week
after being in the ground for two years.
3.
Too little light. Bougies should be in at least half day full sun.
Remember to prune your bougainvilleas after all danger of frost is
past -usually after the middle of March.
Homemade compost is nitrogenous enough to cause them to favor
green growth and not flowers. Suggest cut each plant back by at
least ½ in late March.
Cheers, Frank
Q. I have an 80 year old Italian cypress that is about
75 feet tall. There is sap running from the tree. The sap
seems to be coming from an old place where a branch was sawed off maybe over 20
years ago. It is about 8-10 feet from the base of the tree. I can't
tell if the sap is coming from a place higher in the tree and then dripping off
from where the branch was, or, if the sap is coming from the place where the
branch was itself. I live in Atwater village, and am under Los Angeles'
water restrictions. Is this something to be concerned with?
A. .If the tree is otherwise healthy I wouldn’t worry about it –do
keep an eye on it though. I would also keep a 4” thick layer of bark
mulch underneath the canopy of the cypress. This will help by keeping even the
drying of the soil under the tree and it will decompose to help feed beneficial
microorganisms that live in its root zone.
Cheers, Frank
Q. I have a marathon 3 lawn. It has a
oxalis infestation. Can you recommend a good spray or chemical to use?
A. Oxalis thrives in soils that are dryer than is optimal for
Marathon grass. Once were off water restrictions and you can water your
marathon more frequently the oxalis should abate. Sometimes the seed load
from oxalis infestations make it tough to control even if you water correctly,
if that's the case then the judicious use of pre and post emergent pesticides
may be necessary. For a list of herbicides and their use, please refer to
the University of California Davis page at: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7444.html
Q. Given all the heat is it
now too late to feed roses? Any difference if in pots.
A. Nix
on the rose feeding right now, there's a new pest that loves new growth
called the chilli thrip. Same goes for the
pots.
Cheers, Frank
Q. I have
a large dwarf naval orange that is about 20 years old that is producing
adequate and tasty fruit. The tree is losing lots and leaves and large
branches are dying off. Outside of leaf miner damage I don’t see any
other signs of pests. Do You have any suggestions about what to do with
it?
A. Wait
till after we've had a significant rain (about two months after that actually)
and then re-evaluate. Water restrictions here have made conditions rife for
significant salt buildup in the soil, which can lead to dying off of branches.
A good soaking (2-3 inches of rain) should alleviate that. Do not fertilize
your trees until next year.
Cheers, Frank
Q. Which male ginkgo tree
would work best in a front yard in La Crescenta? We need it as a shade tree and
would prefer a fast grower (fruitless). And, do you know of any
nurseries that sell your suggestion?
A. I would plant Fairmont or Princeton Sentry. They're
going to grow a bit faster than the wider than tall Autumn Gold variety. You
can find them here:
Cheers, Frank
