- Author: Dustin Blakey
Gardeners everywhere are familiar with marigolds. They are not exactly new. However, even though there are so many new types available now, I usually see people planting either the obnoxious pompom-shaped "African" marigolds, or the more diminutive "French" types.
Using place names to describe marigolds is a surprising taxonomic construction since neither type is found in Europe or Africa. In fact the genus Tagetes is native to southern Mexico.
While marigolds are great sources of color in the garden, especially if you deadhead the fading blossoms, there are some more interesting options that can be planted. Breeders have been selecting new species and making interesting crosses. A favorite of mine that is not commonly seen in our area is the signet marigold, Tagetes tenuifolia. Perhaps the easiest to find of this type is the cultivar 'Tangerine Gem'.
'Tangerine Gem' marigolds grow into a compact globe covered with orange (tangerine?) blossoms that need no deadheading. In my garden, I have had problems with earwigs and crickets eating the foliage of other marigolds, but at least earwigs seem to avoid this one. It has fine, dissected foliage that looks more like our native fernbush (Chamaebatiaria millefolium) than the usual marigolds. It tolerates full sun, but like most things in Owens Valley, prefers light shade in the afternoon. Mine started to bloom in mid-July and is exploding with color in these shorter days.
'Tangerine Gem' has edible blossoms, a nice bonus from the landscape! They are slightly bitter, but add interest and color to salads. Make sure you pluck off the petals. The base of the flower is very bitter and unappetizing.
One cool feature of many marigolds is that they are known to be antagonistic to root-knot nematodes. Unfortunately, this is one marigold that doesn't help. Many garden sources cite using 'Tangerine' marigolds, a cultivar of T. patula, to control nematodes. 'Tangerine Gem' is an entirely different plant. The University of Arkansas says that this cultivar may even make nematodes worse, so don't plant it where you've have nematode problems before. If nematode control is your goal, stick with other marigolds that have a good track record.
Chances are slim that you will find this marigold for sale locally as transplants, so the best way to get started with them is to buy seeds. (Thankfully inexpensive in this case.) All marigolds are easy to germinate. You can sow seeds directly in the garden 1/4" deep in April, just put out more than you need and thin out extras. It's usually best to start them inside. Make sure seeds are lightly covered. I've noticed this type starts a little slower than other marigolds, but it makes up for it later, with plenty of growth when the weather warms.
'Tangerine Gem' is a nice annual you should consider planting when you're planning out next year's garden./table>
- Author: Dustin Blakey
You no doubt have noticed that those green bananas you bought at the store a few days ago have steadily turned yellow and are beginning to show some brown spots. Some fruits, like bananas, continue to ripen in some way after they are harvested. We call these “climacteric” fruit.
Climacteric fruit are great if you are selling produce. A grower can pick and ship their fruit while it is immature and depend on it ripening after it's purchased. Gardeners often pride themselves on picking ripe fruit out of their gardens, but it is still good to understand how fruit ripening works, particularly as the season ends in fall.
Many fruits, once they reach a particular level of maturity, will continue to ripen; they are the climacteric fruits. This process is associated with the production of the plant hormone ethylene gas and an sharp increase in respiration. Tomatoes, cantaloupes, pears, apples, peaches, avocados, bananas, and figs are all climacteric fruits; however, their ripening may look a little different for each species.
If you've ever consumed store-bought tomatoes and peaches, you'll note their color and firmness will change, but there isn't an amazing change in sweetness or flavor, whereas pears and bananas transform into a wonderful, tasty treat. That is why home-grown tomatoes are so wonderful, and having fruit trees is still popular despite the hard work needed to maintain them properly.
Not all fruits have this ripening pattern. Grapes, strawberries, pineapple, pomegranate, and citrus are non-climacteric fruits. They tend to last a long time since there is not an ethylene induced burst of respiration. You've probably noticed that citrus fruits taste and look very much the same from the day you get them until you eat the last one. Even non-climacteric fruit eventually will change their character, especially pineapple. It's just not associated with the same burst of physiological activity.
Ripening is an important topic for gardeners to know something about for two reasons: fall harvest and extended storage.
At the end of season you may be tempted to harvest all you can before frost. If a fruit is climacteric, and it is far enough along on the road to maturity, it will continue to ripen. This is handy for tomatoes. Completely immature, green tomatoes may need to be used as such, but if there is a hint of color the chances are good they will ripen on your counter if they did not get too cold. If you have a questionable watermelon in the garden that is underripe, it won't compete the ripening process since it is not climacteric fruit. They need to be picked ripe.
The other key reason as a gardener to understand which fruits are climacteric is to prolong storage. All fruits will ripen more slowly in cooler temperatures, but the ideal temperature varies by fruit. Tomatoes prefer being kept about 50°F but apples are closer to 32°F. Most refrigerators are set around 40°F. If temperatures get too low, then ripening may never happen, but too warm and fruit will continue to mature quickly.
In addition to temperature, climacteric fruit are usually sensitive to ethylene. Not only do they release ethylene gas, but they are very receptive to it. To prolong shelf life and delay ripening, keep ripening fruit away from fruit you are trying to keep from ripening. When you are ready for stored fruit to ripen you can bring it into a warmer location and put it into a bag or with other ripening climacteric fruit to hasten the process.
If you want to experiment with ripening (a good science project to undertake with kids doing distance learning this year) look at ripening pears and bananas. Both are easy to ripen and will show their progress in an obvious way. Underripe fruit are available year-round. Try ripening them at different temperatures, both together and apart.
Now that you know more about fruit ripening, hopefully you will have more options with storing and using produce from your garden and the store.
For more information, see this article which explains the physiology of fruit ripening in much more detail than you really care about. https://core.ac.uk/download/pdf/12042368.pdf
- Author: Carmen Kappos
Wishing you happy gardening during these trying times.
For the original article please go to this link./span>
- Author: Trina Tobey
Living in California, we inevitably get smoke from wildfires in our yards and gardens and this year is no exception. Over 7,400 fires and 3.1 million acres have burned across California so far this year, making 2020 an extreme year for fires on top of COVID-19, protests, an election, and heat waves. But how does all of this smoke and ash affect our plants? I did some research and found that there are both positive and negative effects of smoke on plants.
Positive effects of smoke come from the increase of carbon dioxide. Plants extract carbon dioxide from the air and use it in photosynthesis to feed themselves. If the plant has an ample supply of water and there is enough sunlight shining through the smoke for the plant to use the extra carbon dioxide, the plant can produce more food for itself. At moderate levels smoke can diffuse the light, which can be a relief for plants here in the high desert that are normally exposed to very intense light every day. This is good for the plants but also for us humans and animals who depend on oxygen.
Conversely, smoke and ash particles can coat plants inhibiting photosynthesis. Smoke particulates can clog stomatal pores which prevent the gas exchanges required in photosynthesis which decreases the amount of food available to the plant. Smoke that sticks to plants can be bad for the plants but good for us. Plants, especially fuzzy plants, remove these smoke particles from the air by absorbing them into their leaves and stems and by minerals translocated through the roots. Again, this eventually helps clean the environment.
If plants are covered with smoke and ash, both sides of their leaves should be cleaned with water. As for the produce you eat from your garden, simply washing it with water before consuming it should remove any of the residue you might otherwise ingest.
In conclusion, the good news is that your plants will likely not be harmed by the smoke, especially if you give them a bath. The bad news is that the smoke is still hazardous to us humans.
Luckily, we have the plants to help us out by cleaning the air for us.
Humans can find out current air quality conditions online at airnow.gov./span>
- Author: Alison Collin
I had long ago become resigned to the fact that I cannot grow perfect, blemish-free apples on the two trees that we inherited when we moved to Bishop. There is the challenge of keeping codling moths and aphids under control, thinning prodigious numbers of tiny apples in the spring, and chasing house finches away from the maturing fruit. I have learned to accept peck marks and am happy to remove a codling tunnel or two when canning large volumes, but nothing prepared me for the miseries of an enormous crop of rotted fruit.
Both trees are mature, one being a Gravenstein, the other a Golden Delicious. They ripen about one month apart with the Gravenstein leading the way. This year in spite of the young fruit being thinned and sprayed with Surround, the fruits on both trees were severely affected by codling moths, yet for some reason surface damage on the Gravenstein generally did not go very far into the apple and with a quick flick of the knife it was gone. So when the Golden Delicious started swelling and various small marks and blips appeared on the skin I really did not think too much about them. However, very soon the branches were laden, not with crisp, juicy apples ready to pick, but with brown patches on almost every fruit. Even tiny specks allowed this fungus to enter, and the codling moth damage enabled the fungus to take hold with a vengeance. I thought that I would be able to salvage something to eat from those fruits with minimal damage, but this infection moves fast, frequently entering the fruit through either the calyx or stem and rapidly affecting the core and surrounding tissue and producing the typical fungal odor.
It's likely that a codling moth strike created an opening for some pathogen to enter.
Botryosphaeria species cause "white rot" — a fungus that is extremely common and can affect many woody plants ranging from birch to blackberry and pears to Rhododendron, where it can infect woody tissue and cause cankers. In apples it may infect fruit early in the season without showing, but the rot begins to spread in the warm weather as the fruit matures and shows as circular brown areas.
Brown Rot is caused by a fungus called Monilinia, and it usually affects stone fruits beginning as brown spots which rapidly coalesce to form patches, and then affect the whole fruit. Being primarily a disease of stone fruits, when it does occur on apples (rare), it is usually because the fruit are near infected plums, peaches or nectarines and conditions are optimal for its growth. The sunken brown tissue develops fruiting spores that begin as tiny black spots which then develop whitish heads. Fungicides don't work once the disease has appeared since it enters the fruit through a wound. At the end of the season affected fruits may stay attached to the trees where they shrivel and eventually become mummies, or may drop to the ground, but either way they spread infection through spores being distributed by wind, rain or sprinkler irrigation. Due to our dry climate, brown rot is not a common occurrence in Owens Valley on stone fruits, but it is not unheard of, either.
Photos of fruit infected with a recently recognized fungus, Paecilomyces niveus , look identical to many of the samples from my trees, but the color patterning of the damage looks completely different on other fruits. I hope that it is not this fungus since it produces a toxic substance, patulin which can sicken people, and can survive the high temperatures used in the pasteurizing processing.
A physiological disorder called bitter bit can also cause discoloration, but the lesions are much smaller. It is caused by a calcium deficiency in the developing fruit. (Link to more information.)
Another possibility is a combination of spoilage organisms taking advantage of an opening caused by a codling moth strike. Sometimes it's impossible to tell!
Control of fungal infections is achieved by removing all affected fruit and mummies and disposing of them in some way to prevent the spores from being blown onto other plants. I have buried these in a deep pit, raking up and removing all fallen leaves and pruning out and disposing any twigs that appear to be blighted. Dormant spraying to reduce damage by pests in the following season and thinning fruits early to give plenty of space around each one, monitoring for codling moth and taking appropriate action to control them, should help to control the damage which gives a port of entry for the rot spores. Information on fungicides on backyard apples in California can be found at this page.
I intend to be much more aggressive in taking control measures in future, but since my apple trees are alternate-year bearers, I will have to wait a very long time to know if I have been successful!
For more information about fungal infections of fruit, follow one of these links: