by Matt Lollar | Jun 4, 2018
Normally we think of rust as something that deteriorates metal, but a number of different fungal rusts can affect plants in the garden. Rust disease can affect corn plants, cedar trees, and even blueberry bushes. Just like the broad range of plant species that can be plagued by rust, there are a number of species of rust fungal spores floating around and ready to infest your garden. This article will focus on leaf rust of blueberry.
Blueberry leaf rust on the top of a leaf. Photo Credit: Philip Harmon, University of Florida/IFAS Extension.
Leaf rust of blueberry in Florida is caused by the fungus Pucciniastrum vaccinii. Although the common name of the disease is “leaf rust”, the disease can also infect the stems and fruit of blueberry plants. The disease causes small, round spots visible on the tops of leaves. Spots will multiply and the leaves will eventually yellow and fall off. Young stems and green fruit can also become infected as the disease progresses. Bright orange lesions will form on stems and fruit as the thousands of microscopic spores conjoin. The clusters of spores are easily wiped or washed off of plant material. When spores dry out, they become airborne and can be transferred to nearby plants.
Blueberry leaf rust on fruit. Photo Credit: Philip Harmon, University of Florida/IFAS Extension
The rust fungus thrives in hot, humid, wet conditions. A number of cultural practices can be adopted to reduce disease progression and survival.
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Irrigation
Disease persistence can be reduced by limiting the amount of water that contacts the plant leaves. Water the base of plants or install drip irrigation for your bushes rather than watering from overhead. If overhead irrigation is the only option, then water plants in the morning rather than in the evening. This allows the leaves to dry out over the course of the day.
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Pruning
Removal of approximately 25% of the oldest canes in late winter before spring growth begins will stimulate the production of new canes and should result in plants with canes of different ages and will provide a good mix of vigorous branching and fruit production. Moderate summer pruning can also improve yield and shoot growth. When pruning, cut out vigorous shoots that are growing well beyond the desired canopy height and are in the interior portion of the bush. This will promote a more open growth habit and help with air circulation on the remaining plant material. Some vigorous canes developing from the ground and growing on the outside of the bush can be topped to stimulate branching and flower bud formation.
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Mulch
Pine bark mulch helps with establishment of young plants and helps keep soil pH low in existing plantings. A layer of aged pine bark 3 inches deep extending about 2 feet out from the plants will provide a good growing medium for surface feeder roots. Pine straw can be used if pine bark is unavailable. Mulch also moderates soil temperature, helps keep weeds at bay, and adds organic matter to the soil. Make sure to keep mulch raked back about three inches away from the plant canes to provide good air circulation to the roots.
Hopefully this article has given you some tips to have a good blueberry crop for years to come. For more information on growing blueberries in Florida, please visit the University of Florida/IFAS EDIS Publication: Blueberry Gardener’s Guide.
by Matt Lollar | Apr 23, 2018
Recently, an Extension Agent in the Florida Panhandle received a picture of some mushrooms popping up in a client’s garden. These particular mushrooms were in a spot where leftover mushroom compost had been dumped. The compost was previously used to grow oyster mushrooms and the client was hopeful that she had more oyster mushrooms growing in her yard. Unfortunately, the lab results came back stating the mushrooms in question were Armillaria spp.
Armillaria spp. in the garden. Photo Credit: University of Florida/IFAS Extension.
Armillaria spp. cause root rot of trees and shrubs throughout the world. The fungus infects the roots and bases of trees, causing them to rot and eventually die. Some species of Armillaria are primary pathogens that attack and kill plants, but most are opportunistic pathogens that are attracted to unhealthy or stressed plants. Fruiting structures of the fungi can be recognized by the clusters of yellow to brown-colored mushrooms that emerge during wet conditions. However, the mushroom caps sometimes never form and the plant material needs to be inspected more thoroughly to find the disease culprit. Infected plants may have wilted branches, branch dieback, and stunted growth and should be removed and replaced with resistant species.
White mycelial fan under the bark of a root infected with Armillaria tabescens. Photo Credit: Ed Barnard
Management – The best method for controlling Armillaria root rot is with proper plant installation and maintenance. Planting plant material at the proper depth will allow the roots to breathe and reduce the opportunity for the roots to rot. Pruning tools should be sanitized between plant material. Proper irrigation and fertilization will also reduce the risk of plant disease and root rot. Lastly, you can choose to plant a diverse landscape with resistant species.
For more information on Armillaria root rot and a comprehensive list of resistant species, please view the EDIS publication: Armillaria Root Rot
by Matt Lollar | Mar 13, 2018
This late winter has been alternating between warm and cool extremes. One thing is for certain and that’s that it’s time to start planning your sweet potato crop.
Sweet potatoes are generally planted March through June in the Florida Panhandle. The most common method of planting is with sweet potato slips. Sweet potato slips are simply six to eight inch cuttings of a sweet potato vine with the majority of the leaves pulled off. You can purchase sweet potato slips from a local garden center or a seed catalog. Make sure you only purchase certified, disease free slips. You can also easily start your own sweet potato slips from a store-bought sweet potato.
Sweet Potato Slip Production
- Pre-sprout Your Tubers – Place sweet potato tubers in a warm place (75 to 85 degrees) with high humidity (90%), such as in your garage, for two to four weeks. It is important that you put the tubers in a well-ventilated container. Allow the tubers to stay in the pre-sprout area until sprouts are roughly 1/4-inch in length.
- Bedding – Sweet potatoes are placed in “beds” to produce slips. A sweet potato bed can be made out of the same materials as you’d use for a raised bed garden. You can simply build a frame out of 2″x12″ lumber. Plastic is placed in the bottom of the beds before a layer of bedding material is put down. The bedding media can be a peat-based potting mix or a more economical substrate would be wood chips or sawdust. Sprouted sweet potatoes should then be placed in a single layer 8″ to 12″ inches apart and covered with two additional inches of bedding material. Then top dress the bed with a general purpose, granular fertilizer, water the bed, and cover with clear or black plastic. Poke holes in the cover plastic to aerate the soil and prevent carbon dioxide and temperature buildup. You may need to water the bed periodically, but do not completely saturate. Sweet potato slips can also be produced in the garden if you have a sandy, well-drained soil such as the field pictured below.
Sweet potato slip production in the field. Photo Credit: Evan Anderson, University of Florida/IFAS Extension.
- Cut Slips – Slips will be ready to cut in seven to ten weeks. Cut slips 1″ above the bed surface and trim to 10″ to 12″ in length. Strip all but the top one or two leaves from each slip. If you are unable to plant your slips at the time of cutting, then store them in a cool, dry area to prevent them from rotting.
Rooted sweet potato slips that are ready to transplant into the garden when the soil becomes warm.
Barbara H. Smith, ©2016 HGIC, Clemson Extension
Sweet Potato Production
Sweet potato slips can be planted March through June in the Florida Panhandle. Plant the slips at least three nodes (leaf stubs) deep at 12″ by 36″ spacing. Fertilize based on soil test recommendations. Sweet potatoes are ready to harvest generally between 100 to 120 days after planting slips. After harvest, you will need store your sweet potatoes in a warm (80 to 85 degrees), humid (80 to 90%) place for one to two weeks to allow them to “cure”. After the curing period, you can store your sweet potatoes in a cool area (55 to 60 degrees) until you are ready to eat them.
Sweet potato storage on a commercial farm. Photo Credit: Evan Anderson, University of Florida/IFAS Extension.
by Matt Lollar | Feb 14, 2018
Register today for the 2018 Panhandle Fruit & Vegetable Conference! The Panhandle Fruit & Vegetable Conference is scheduled for February 19th & 20th. On the 19th we will go on an afternoon farm tour in Baldwin County, AL that will end with dinner (included) at Auburn University’s Gulf Coast Research and Extension Center in Fairhope. Educational sessions with guest speakers from University of Florida, Auburn University, and Texas A&M University will be held on February 20th where topics will include Citrus Production, Vegetable Production, Protected Ag Production, Marketing/Business, Food Safety, and Fruit & Nut Production. A full list of topics can be found here. Fifty dollars (plus $4.84 processing fee) covers the tour and dinner on the 19th and educational sessions, breakfast, and lunch on the 20th! The complete agenda is now available. Use your mouse or finger to “click” on the image below for full screen viewing.
Make sure to register by Wednesday, February 14th! – Registration Link
by Matt Lollar | Jan 25, 2018
We’re having a cold winter this year and I’m sure the last thing on your mind is your spring garden, but it’s time to start ordering seeds! The spring gardening seed catalogs are now out on garden center magazine racks and it’s tempting to buy everything that looks good in pictures. However, there are a few things to think about when picking out what you want to grow.
Know Your Season
Vegetable crops are usually grown by season. We are lucky in Florida because we have both a warm season and a cool season. We are unlucky too because we have very hot summers! Usually our spring crops suffer from too much heat and humidity in July and August. Cool season crops are typically planted from September to March, while warm season crops are typically planted in February and March or August and September. Eggplant and okra are outliers because they can usually make it through the summer. It’s important that you follow tried and true planting dates for the crops you intend to grow. You can find a very helpful table embedded in the Florida Vegetable Gardening Guide that lists what to plant when.
Know Your State
As you may have noticed, North Florida has a very humid climate year-round. We not only have to give our crops extra care due to rain and humidity, but we also need to grow varieties adapted for our climate. Some recommended varieties are listed in Table 2 of the Florida Vegetable Gardening Guide. You can also find some recommended varieties in Seed Sources for Florida Homegrown Vegetables. (Please note that some of the seed sources listed in this publication are geared more toward commercial growers, so they may be unavailable unless you intend to plant quite a few acres in one crop.)
Know How Green Your Thumb Is
Probably the most important thing about gardening is your level of commitment and experience. Take a few minutes to assess your skills as a gardener and the amount of time you are willing to commit to your garden. Then use the following list to help you determine what to plant.
- Easy to Grow in Florida – Radish, Collard, Turnip, Kale, English Pea, Green Bean, Sweet Potatoes
- Somewhat Easy to Grow in Florida – Okra, Yellow Squash, Zucchini, Eggplant, Watermelon, Sweet Corn
- Hard to Grow in Florida – Tomato, Cantaloupe, Muskmelon, Pumpkin
This is only a short list, but I hope it gives you a starting point to help you determine your skill set.
A variety of calabaza squash. Photo Credit: University of Florida/IFAS
Know the Difference Between Open Pollinated, Heirloom, and Hybrid Varieties
- Open-pollination of crops occurs when insects, birds, wind, or other natural mechanisms carry pollen from flower to flower. Seed can be saved from open-pollinated varieties which will produce crops with similar characteristics to their parents.
- Heirloom varieties have a history of being passed down within a family or community. As the name suggests, seed can be saved from heirloom varieties which will produce crops with similar characteristics to their parents.
- Hybridization is a controlled method of pollination in which the pollen of two different varieties or species is crossed by human or natural mechanisms. Seed saved from hybrids will most likely not produce as vigorously as their parents and may produce crops that are significantly different from their parents.
I would never want to discourage you from growing new crops, but I hope you now have a little better plan as to what to plant this year. If you want to try something new with minimal risk then I would recommend you try growing yard-long beans, calabaza squash, and malabar spinach. These vegetables serve as excellent substitutes for some of the more commonly grown varieties. You can read more about these crops and other minor vegetables by visiting the University of Florida/IFAS Minor Vegetable Webpage.
