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December 2011
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March 2012

Fava Bean Rust

This is a plant with a severe case of fava bean rust, or Uromyces viciae-fabae.

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No, the plant is not oxidizing. Rusts are plant diseases that give the impression of rusty spots, but really those are pustules (great word eh?) containing fungal spores. Most of the fungus consists of threads called hypae that are all tangled through the plants, robbing them of nutrients in plant sap. The spores released at the surface are ready to float away and find a new plant to infect. Here are some close up shots of the spore pustules:

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I see the disease fairly often in San Francisco gardens. It does probably reduce production somewhat, but it often occurs later in the season, after most of the crop has formed. Here are some ways to lessen your chance that it will occur or reoccur:

--This disease is encouraged by wet leaves, so try to water favas at the ground level, rather than sprinkling them. Of course we can't prevent rain and misty weather, but the less dampness the better.

--If you see the disease early, with only a bit of damage, you might slow it by removing diseased leave, though of course you don't want to take too many leaves off of the plant.

--If your plants are ripening beans, you will be reluctant to take them out until you harvest, but as soon as you can do so, take th plants out. Do not compost them. In San Francisco, you can put them into a green bin for Recology to compost, since their compost gets very hot and should kill the spores. When you take your plants out, pick up all the fallen and dried leaf debris you can find as well.

--Don't save and replant seed that came from infected fava bean plants.

--Copper sprays, which are approved for organic farmers, may offer some control. However, they will be a lot of trouble for a small planting, and will harm the soil if used repeatedly.

--A two to three year rotation might help, but if your garden is open to breezes from nearby plantings, the spores may be reintroduced.

(See also on this blog posts on chocolate spot disease and the black aphid that infests fava beans.)


Strange Winter Weather Shows in the Garden

We ate the last of the 2011 cucumbers on January 12th. This is a good 2 months later than I usually eat my last cuc. (see photo on post of December 30th, 2011). That's the good side of our continuing mild, sunny, San Francisco winter. But there are downsides too.

One downside is that leafminer flies have continued to fly, mate, and lay occasional eggs on my chard plants. The chard at City College has lost several leaves to their damage. By this time of year, the flies have usually died or are dormant pupae in the soil. It hasnt been so bad that there is no edible chard, as can sometimes happen in summer, but I am surprised to see ANY at this time of year.

     Another is that my apple tree had flowers on it in November into December. Not supposed to happen until April! (Ours is a late bloomer.) So that's energy the tree is wasting that it could be spending on making leaves, flowers, and fruit next year.

    And then there is miner's lettuce. Or, that is, there is no miner's lettuce. Usually by this time of year I have been making delicious salads from this California native plant that comes up freely in my garden. It is usually beginning to appear by November, and I have enough for the first salad in the first or second week of December. But this year, by mid-January, I have seen only a few very small seedlings

This is what I am usually seeing by this time of year:

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     This is a mature miner's lettuce plant, about 15 inches across and a foot tall. The mature leaves are round, with the flower stem coming from the middle of the leaf. The whole plant is delicious and replaces much of the lettuce in my salads from December through mid April.

This is what I saw today, January 15th, 2012:

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     There are only very young miner's lettuce plants like this one. They are about 4 inches across and low to the ground. The young leaves of miner's lettuce (on this plant nibbled a bit by a slug) are spatulate--sort of triangular. The mature, round leaves haven't even begun to show up yet, and it looks like there won't be any for a couple more weeks.

Today on the Prairie Home Companion, on National Public Radio, I heard Garrison Keeler talk about how the lakes in Minnesota were finally frozen solid so the ice fishers could fish safely, and how glad everyone was for the single digit temperatures. Well, I would prefer double digit, myself, and mostly above freezing, but I do have reasons to prefer our normal winter weather.

Tonight it is colder than it has been for several weeks and rain is predicted for next week, so maybe our wait for winter is at an end. But does the weather so far mean a shorter miner's lettuce season? Hope not.

Are any plants or pests acting differently due to the mild winter in your garden?

 

 

 


More on Native Dogwood, other California Natives

I finally found the image of flowers from the plant shown in my last post with berries. Here it is, as taken on May 15th, 2011.

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It's a grab shot, and I think it isn't quite in focus, but you can plainly see that the flowers have 4 petals, so at this stage, you can tell (I should have seen) that it is not a viburnum, which would have had 5 petals. As you can see the leaves look better in May than they did by the time the plant had matured berries.

     It is apporaching time to see the spring wild flowers on hills near SF again! In anticipation, here is a photo I took on May 2nd of 2011, on a trail above College of San Mateo. It shows a mix of plants. The ones I can identify are a blue Iris douglasii and a yellow version of paintbrush. That is prrobably coastal paintbrush, Castilleya latifolia, since the bracts (that look like flowers) of that species can be yellow as well as red. C. latifolia is native to coastal, central California.

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The Iris you can grow in your garden, the paintbrush, not so much, since it has a semi parasitic relationship with adjacent plants that is hard to get underway on purpose.

These spring-like winter days make me ready for spring, though with an ominous feeling that we need some rain to make those spring flowers bloom!

 


Who knows what this is?

In mid-November we wee walking on San Bruno Mountain, at the south end of San Francisco when we came upon this plant with white berries. I think it's a California native shrub, but I don't know its name. My best guess is a viburnum, but I am only about 20% confident of that guess. So this time, I put the question to you who are reading this blog. Do you know what species this is?

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In the spring, this plant had flat clusters of white flowers. I shot those too, but don't remember the exact date, and don't know if I can find the images.So, any guesses from just this photo?