Friday, March 3, 2017
March Plant Information Soils Class Outline
I'd like to thank all who attended my soils class -here's a copy of the outline for you if you didn't get one in class:
The Universe Below: What You Need to Know, and the Amazing
Things You Probably Don’t Know About How Soils Work
1.
Soil Formation
2.
Physical and Chemical Properties of Soil
a.
Soil types
b.
Worm test
c.
Cation exchange capacity (Cal soils have high)
d.
Density
e.
Aggregates
f.
Porosity
g.
Rapid Backyard Composting
i.
½ green, ½ brown
ii.
Not a good idea on natives and N sensitive
plants
iii.
Pieces no larger than 1 inch
iv.
Turn, water and burn
h.
pH
i.
Salinity (drought related salt buildup)
j.
It’s a jungle down there (earthworms etc.)
k.
Fungi
3.
Soil and Water
a.
Soil Capacity
b.
PWP
4.
Soil Fertility and Plant Nutrition
a.
Essential and secondary nutrients
5.
Fertilization of Garden Soil
a.
Organic vs. Inorganic
b.
Availability over time of O vs. I
c.
Containers
6.
Soil Properties
a.
Soil Amendment
b.
When and Where to Amend
c.
Rates
d.
Perc Test
e.
Preventing Soil Breakdown
i.
Planting, Wetting drying, Bacterial
decomposition, Amendment
ii.
pH modifying
7.
Potting and Container Soil
a.
Perched water tables
b.
Osmotic potentials
c.
Drainage
Saturday, February 18, 2017
It's Not Fruit; It's Manzanita Leaf Gall Aphids
Yesterday this came into my office:
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| Fruit-like galls on the newer leaves of a manzanita. |
It's a Manzanita (Arctostaphylos) with what look like berries or peppers growing near the top of the plant. Turns out they are the handiwork of the manzanita leaf gall aphid (also called the manzanita leaf-fold aphid), a plant juice sucking insect that injects just the right mix of plant-hormone like substances into the manzanita it's feeding on to cause the leaf to pucker up and color up and look just like a fruit. This protects the aphid from predators and doesn't seem to hurt the manzanita much. It is caused by animal browsing, pruning or fertilization as the soft new growth that follows any of these actions is highly susceptible to infestation by the aphid.
 |
| Manzanita leaf gall aphids visible after dissection of the gall with a razor blade. |
Manzanita Leaf Gall Aphid Links
- Manzanitas - UC Master Gardener Program of Sonoma County
- Red Leaf Galls on Manzanita in Arizona's Sycamore Canyons
- Manzanita Leafgall Aphid (Tamalia coweni) · iNaturalist.org
- Pseudo-peppers, Manzanita Leaf-gall Aphid (Tamalia coweni) - The Firefly Forest
- Pests of Landscape Trees and Shrubs, Third Edition: An Integrated Pest ... - Google Books
- Manzanita Leaf Gall Aphid - Tamalia coweni - BugGuide.Net
Wednesday, February 1, 2017
Saturday, January 21, 2017
South Pasadena Ailing Avocado
 |
| Area underneath Avocado tree. |
 |
| South Pasadena Ailing Avocado |
Q. I live in South Pasadena and we have an avocado tree that is more than 50 years old that appears to be dying. The canopy has shrunk significantly, the leaves have brown edges and are falling and there are a lot of dead branches. In addition, the tree is producing less and less fruit each year.
We've tried to increase watering the tree, but it does not appear to be helping. Any recommendations to help save our tree?
A. You actually have a very lucky
tree; the conditions I see in the photo are not the best for avocados.
The area underneath an avocado
tree should be free and clear of lawn and high amounts of soil compacting human
activity. Also, the best thing to have underneath an avocado tree’s canopy is a
thick carpet of its own fallen leaves.
The avocado’s leaves decay to from
a substrate that is perfect for those organisms and microorganisms, insects,
worms, protozoa, bacteria, fungi, nematodes etc. which are beneficial to the
avocado. Add to that the fact compacted soil tends to be devoid of these
organisms and the amount of water that the lawn underneath the tree needs to
keep it green is an ideal breeding ground for a type of fungi-like organism (Phytophthora) that eats avocado
roots for dinner, and you have the perfect recipe for the slow but sure demise
of your tree.
Also, the drought has probably
caused considerable salt buildup underneath the
root zone of the tree. Fortunately, these recent rains should take care of
that.
So what to do? Remove all lawn
from underneath the canopy of the tree (on both sides of the fence if
possible). Apply horticultural gypsum to the soil at the rate of about 25
pounds scattered throughout the area underneath the canopy, then lay down a 5-inch-thick
layer of shredded (if you don’t have squirrels or rats, they love the shredded
stuff) or small sized (this one’s the best) fir bark underneath the entire area
underneath the canopy of the tree except for an are 4-5 inches from
the trunk (you don’t want the fir bark piled up against the trunk, that can
cause a condition where the tree’s bark becomes infested with insects and
fungus owing to the humidity raising and fungal spore nurturing nature of the
fir bark). Also Then allow the avocado’s soil nurturing leaves to remain where
they fall in Perpetua.
Do not feed your avocado much;
high nitrogen levels in the leaves and tissues favor pest infestation. Use
about ½ strength Avocado/Citrus food just once a year (in November -it’s too
late now). If you have a problem with leaves falling off after this, it is most
probably Persea mite. This
pest is mostly a nuisance but during the drought has become more than that,
causing total defoliation in some cases. It can be controlled using horticultural
oil and cultural management.
Please let me know how these
measures are working or not in about six months’ time.
Saturday, January 14, 2017
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