Tuesday, June 28, 2016

Dying Maple (maybe) Tree

Q. I have this maple tree (I think) has been deciduous since October 2015 and one small branch has a few leaves in the spring. But now it seems to be dying. Can you give me some input what to do? Totally cut down or wait and see? I appreciate your input, thanks!

A. The tree (I think you have a Liquidambar not a maple), appears to be quite dead. The fact it has not leafed out by now is a major consideration in this. You need to take it out as soon as possible as dead trees are 100% likely to fail in the next several years. It is important that you chip the tree completely to pieces that are one inch or less and solarize the chippings for at least 6 weeks (in winter at least three months: see solarizing guide on second page of pamphlet here ) so that if the tree was infested with Polyphagous shot hole borer (PSHB) it does not infest other trees. Many maples and the Liqudambar tree are hosts for PSHB. 

Tuesday, June 14, 2016

Pink Lemonade Tree Suffering in the Pot

Q. Frank, this is a variegated leaf pink lemonade lemon tree bought last December. The fruit you see were present when bought.  You will notice there are several dropped leaves on the planting soil and I an eager to know what is causing them to drop.  The tree is watered irregularly but last week I hyper-saturated the soil when I neglected to move the hose in a timely fashion.  

Assuming the cause of the dropping may be insect related, the tree was sprayed two times in four days with neem oil. Now the question is what is causing the leaves to drop?  Was it my one-time over-watering? A combination of the over-watering and the neem oil? Would the over-watering cause the roots to become waterlogged? Will the leaves eventually start to grow back?

 I found the following bag of ‘garden soil’ with only a small quantity of content left in the bottom of the bag.  This leads me to the assumption this is what I probably used potting the lemon tree. While I might have mixed it with some other remnant gardening product found around the garage, soil or mix, this product probably represents the vast majority of the what I used. Visually this garden soil looks similar to what is in the pot around the lemon tree. Hopefully this product identification addresses your question, resolves the issue and provides a reasonable platform for further discussions and a solution/conclusion to the continuing episode of “The Falling Leaves". 

A. One of the most important components of potting soil is not the organic material, but the inorganic material that provides for drainage. Drainage is the word used to describe the soils ability to allow water to move through it. Media that is heavy in organic material prevents water from moving through it because there are few if any spaces for the water to travel, and a plethora of compounds and surfaces that actually cling to water (they are called hydrophilic compounds). This allows for a root-space that eventually becomes devoid of oxygen, a primary factor in root growth.

The substance in the bag that you have sent me a picture of is organic compost replete with lawn trimmings and table scraps. This product is fine to add to a garden where it is to be dug in and diluted with the sand, clay and silt that is already present in the garden soil, it is however, sheer poison if used alone in a pot. Not only does the water added to the pot saturate the root space and displace life giving oxygen, but the table scrap compost starts to ferment without oxygen. This anaerobic fermentation of the compost produces toxic compounds and gasses that hasten the death of the already oxygen starved roots. Having a hole in pot filled with this vile mix does little to improve the conditions as a physical force called the “capillary force” that is powered by waters’ attraction to small, cylindrical linear spaces keeps the water the soil like the two components of Velcro keep each other well attached.

So, as I suggested, you need to either replant the citrus in a pot with ½ cactus mix and ½ “potting soil “ (make sure the bag specifies the word ‘potting’) or replant a new one in the same. I would start with a new plant, as the weakened condition of the tree has made it labile to disease and has increased the possibility that if you transplant it, your will also transplant a large quantity of disease producing fungal spores (like Phytophthora, see video of spores) as well.

Saturday, June 11, 2016

Thursday, June 9, 2016

Links for Plant Information Class Tour of New Collection Items

Various New Introductions

Australian Native Plants • About • 800.701.6517
brachychiton bidwillii - Google Search
Brachychiton gregorii F.Muell.: FloraBase: Flora of Western Australia
Cassia brewsteri - Google Search

Eucalyptus Accessions

Pacific Horticulture Society | Small Eucalyptus for Western Gardens
Eucalyptus conica inaturalist
Cider Gum - Monrovia - Cider Gum
Angophora costata - Google Search
Angophora costata - Google Search
A Communion with the Miena Cider Gum | Tasmanian Geographic | by David Tng
Eucalyptus conica : Apple Box | Atlas of Living Australia
Eucalyptus delegatensis : Alpine Ash | Atlas of Living Australia
Eucalyptus delegatensis Tasmanian plants key
Eucalyptus delegatensis forests
Eucalyptus regnans
Eucalyptus regnans Mountain Ash | The Wood Database - Lumber Identification (Hardwoods)
Eucalyptus delegatensis Victorian ash, also known as Eucalyptus delegatensis - Species
Eucalyptus delegatensis Description and range in NSW
Eucalyptus 'Moon Lagoon' at San Marcos Growers
Eucalyptus 'Moon Lagoon' • Australian Native Plants • Plants • 800.701.6517
Eucalyptus caesia
Eucalyptus caesia Benth.: FloraBase: Flora of Western Australia
Eucalyptus caesia 'Silver Princess' / Library − Speciality Trees
Cassia brewsteri | Flickr - Photo Sharing!
Cassia brewsteri Golden Glamour Super Jammer - Cassia brewsteri — The Plant Provocateur
Eucalyptus erythronema - Wikipedia, the free encyclopedia
Eucalyptus erythronema Turcz.: FloraBase: Flora of Western Australia
Eucalyptus erythronema • Australian Native Plants • Plants • 800.701.6517
Eucalyptus erythronema
Eucalyptus erythronema
Eucalyptus erythronema Cal Poly selectree entry
Eucalyptus forrestiana / Library − Speciality Trees
Eucalyptus forrestiana • Australian Native Plants • Plants • 800.701.6517
Eucalyptus forrestiana -Fuschia gum
Eucalyptus forrestiana - Wikipedia, the free encyclopedia


Acacia cognata - Google Search
Cassia brewsteri syn Senna brewsteri • Australian Native Plants • Plants • 800.701.6517
Acacia cognata Cousin Itt ['ACCOG01'] PP25,133 at San Marcos Growers
Acacia cognata 'ACCOG01' Cousin Itt Little River Wattle - Monrovia - Cousin Itt Little River Wattle
Future Plants by Randy Stewart: October 2011
Edible Seeds
Acacia murrayana Seed Pod. - CSIRO Science Image - CSIRO Science Image

Austalian Grasses

Austrostipa ramosissima - Google Search
Austrostipa ramosissima at San Marcos Growers
Cal-IPC: California Invasive Plant Inventory

Chilean Plants

Cistanthe grandiflora 'Jazz Time' at San Marcos Growers
Cistanthe grandiflora - Hierbas Chilebosque
Francoa ramosa at San Marcos Growers
Maytenus boaria at San Marcos Growers
Ochagavia litoralis at San Marcos Growers
Ochagavia litoralis - Wikipedia, the free encyclopedia
Ochagavia | San Luis Obispo Botanical Garden
Maytenus boaria 'Green Showers' - Trees - Plant Type - Boething Treeland Farms
Azara microphylla Box-Leaf Azara - Monrovia - Box-Leaf Azara
Azara microphylla - Wikipedia, the free encyclopedia
Azara (plant) - Wikipedia, the free encyclopedia
Azara microphylla 'Variegata' at San Marcos Growers
Puya coerulea var. coerulea at San Marcos Growers
Puya coerulea var. montanoa - Buy Online at Annie's Annuals
Puya coerulea image