Sweet Potatoes for the Summer

Sweet Potatoes for the Summer

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

  1. 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.
  2. 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.

  3. 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.

Saving Seed

Saving Seed

You’ve grown some wonderful vegetables, annuals or perennials and you would like to save some of the seed from those plants to have for planting in the future. This is a great way to get more of the plants you know and love while saving on the expense of new plants. One exception are plants that are F1 hybrids; seeds from these plants will produce crops quite dissimilar to the parent.

First, you need to collect ripe seed from the desired plants. How do you know when the seeds are ripe and ready to harvest? The strategies for annuals/perennials and vegetable plants differ.

The ripe seedhead of a coneflower. Photo credit: Mary Derrick, UF/IFAS Extension.

The ripe seedhead of a coneflower. Photo credit: Mary Derrick, UF/IFAS Extension.

For annuals and perennials that flower without making a fruit, wait until the flower has dried up and the seed head is brown and dead-looking. The seeds are then mature and ready to harvest. Take a look at the photo of the coneflower seedhead for reference. These seeds are already dry and can be put into an envelope and then into a sealed jar or plastic stage bag that contains a desiccant to absorb any excess moisture. There are a few options for desiccants: the little packets that come in vitamin bottles and purses to keep them dry, cornmeal or dried milk in bottom of the bag. Be sure to label your envelope with the date and name of your plant seeds. Store in the refrigerator.

When you are saving seed from a vegetable that has seeds inside it such as a tomato, pepper or squash, harvest the vegetable when it is ripe and ready to eat and scoop out the seeds and wash away all other plant parts from the seed. These seeds are very moist and if stored in this state, they will rot into a mess. You want to get the moisture content below about 8% for long term storage. There are several methods:

  • If the humidity is low and the temperature high, (I know, those can be rare conditions for Florida) you can put the seeds in a single layer on a baking sheet in the shade to let them dry all day.
  • Another option is to take that baking sheet with a single layer of seeds and put it in a 100° oven for 6 hours with the door open. It’s crucial to monitor your oven temperatures as those above 100° will kill the seeds.

Once the seeds are dried sufficiently, store them as described above for flower seeds. Your seeds can then last for several years.

For more information:

Seed Saving from Colorado State Extension

Saving Vegetable Seeds from University of Minnesota Extension


Divide Perennials in the Fall

Divide Perennials in the Fall

After a few years, many perennial plants have grown so large that they need to be divided in order to be revived. Overcrowding causes them to bear fewer flowers and, sometimes, to die in the center. Fall is a good time to divide perennials that bloom in spring and summer and are now done blooming for the year. This is a great way also to expand your perennial beds or share some of your perennial favorites with friends and neighbors.

Vibrant blue Stokes' aster. Photo credit: UF/IFAS.

Vibrant blue Stokes’ aster. Photo credit: UF/IFAS.

Some examples of perennials to divide in the fall are:

  • Stokes’ aster, Stokesia laevis
  • Daylily, Hemerocallis spp.
  • Black-eyed Susan, Rudbeckia hirta
  • Yarrow, Achillea millefolium
  • Crocosmia, Crocosmia spp.
  • Flax lily, Dianella tasmanica ‘Variegata’
  • Liriope, Liriope muscari
  • Cast iron plant, Aspidistra elatior

The first step is to dig out the entire clump. If there is enough clearance in the garden bed, start digging about six inches out from the plant and dig straight down beyond the root zone. It’s best to get as much of the roots as possible to lessen the shock of transplanting. If the clump is too heavy to remove, make your divisions right there with a sharp blade, trowel or shovel. Often, you can just pull them apart with your hands.

Before replanting the divisions, consider adding some nutritious compost to those areas of your garden bed to ensure healthy plants. Be sure to replant as soon as feasible to protect the roots from drying out. After replanting, water the transplanted divisions well and mulch appropriately.

To explore further please see:

Gardening with Perennials in Florida

Propagation of Landscape Plants


You Can Propagate Memories

You Can Propagate Memories

There are a number of plants in my landscape that bring back fond memories – plants that I propagated.

Red Mulberry. Photo credit: Vern Williams, Indiana University, bugwood.org.

Red Mulberry. Photo credit: Vern Williams, Indiana University, bugwood.org.

There’s a mulberry tree in my backyard that I rooted years ago. I took the cuttings from an old mulberry tree in my hometown. As a boy, I climbed the tree, got in trouble once for coming home with mulberry stains on my clothes. I liked the berries and still do. I have good childhood memories about the tree.

About twenty years ago I visited the property adjacent to my childhood home. The tree was still there. It was during mulberry season. I enjoyed a few mulberries. I took about eight or ten cuttings from the tree. About a year after my visit, the property sold. The new owner bulldozed the tree.

But because of the cuttings that I rooted, the tree still lives and not just in my memory. The trees produced by those cuttings are genetically the same as the parent tree. Essentially, they are clones. The one in my backyard produces mulberries each year.

You too can propagate memories. Not all plants can be propagated from cuttings but many can be. Sometimes trial and error is necessary to learn proper timing in taking cuttings. But most reliable references will provide the time of year to take cuttings based on the plant species.

Stem cuttings should be removed from the parent plant with a clean, sharp knife or pruner. Ideally your cutting should be 4-6 inches in length and not much thicker than a pencil in diameter.

Take the bottom two-thirds of leaves off on each cutting. The cuttings should be stuck upright in a propagation medium. I usually use a good quality potting mix and mix in a little course sand or perlite for better drainage. The cuttings should be inserted deep enough to hold them upright, usually ½ to 1 inch.

To help promote rooting of moderate to difficult to root plants, wound the cuttings by scraping the lower ½ to 1 inch of the stem with a clean, sharp knife. The scrape should remove the bark or “skin.” Then dip the cutting in a rooting hormone covering the scrape with the rooting powder prior to inserting the cutting into the rooting medium.

I usually use a four inch pot, gallon size pot or bedding plant flat with drainage holes as a rooting container. I may stick as many as ten stem cuttings in a gallon size pot. I place the container of cuttings in a shady location outdoors and keep it moist. The cuttings should produce roots in two to sixteen weeks, depending upon plant species and the environment.

After the cuttings have rooted, carefully remove them and individually plant each rooted cutting in its own four inch to one gallon size pot. Keep the potting medium moist but not soggy. After the roots adequately fill the pot, the plant should be strong enough to be planted in the ground.

As your rooted cuttings grow, hopefully they will provide fond memories.



An easy to care for perennial to add to your flower garden is the coneflower, Echinacea purpurea. The daisy-like flowers stand tall above the foliage on sturdy 2 to 4 foot stems. Blooms appear about the last part of April or the first of May in the Florida panhandle and last throughout the warm season until late fall. This Florida native reliably comes back year after year. Plant coneflower in part to full sun in rich but well-drained soil for best results.

white coneflower

White coneflower. Photo credit: Mary Derrick, UF/IFAS Extension.

Coneflowers are traditionally purple but many new colors and variations of their form have become available from the horticultural industry. You can find them in white, yellows, pinks, oranges, and greens as well as all shades of lavender and purple. No matter what color you choose, the blooms will attract a host of butterflies and other pollinating insects. In order to protect these delicate creatures, avoid the use of pesticides when they are present.

Once you have a few coneflowers, you will notice that the clumps will grow in time and new plants will sprout from seeds left behind by the spent blooms. In our demonstration garden, this has created a stunning display that has been allowed to take over one of the garden beds. When any one clump gets too big, the number of blooms can decrease and it may be time to dig up the clump and divide it. This is a great opportunity to expand your coneflower bed or share them with some friends or neighbors!

For more information:

Ornamentals for your landscape

Butterfly Gardening


Florida Native Plants: Beautyberry

Florida Native Plants: Beautyberry

This autumn you may notice shrubs with long, arching branches sporting clusters of shiny purple berries. That beautiful sight is the Beautyberry, or Callicarpa americana. This native is found throughout Florida and the southern United States, west into Texas and north to Tennessee and Virginia.

beautyberry branch with fall berries

Beautyberry in the fall. Photo credit: Mary Derrick, UF IFAS Extension.

In the spring, lavender flowers adorn the branches and are a favorite of bees. The flowers eventually give way to the shiny purple berries in the fall. Birds find the berries very attractive and will feast on them when found. Mockingbirds and cardinals are especially fond of them. If you plant this shrub for the birds, one or two plants will provide more than enough of the berries to satisfy their appetites.

Beautyberry is adaptable to a wide variety of soils and moisture. After it gets established it is drought tolerant, however it can also do well in a moist area. A spot in your garden that gets partial sun is a perfect location. Plants in too much sun sometimes get a bit yellow and those in too much shade get leggy and don’t set as much fruit. Beautyberry is deciduous, meaning that it will lose all its leaves in the winter. Therefore, you may want to place it in an area of your yard where it won’t be a focal point in the winter.

This lovely plant is usually readily available at independent nurseries. If you prefer to grow your own, beautyberry is easy to propagate and grows rapidly. Snip off an approximate 6-inch piece from the end of a stem; the cut piece should have 5 sets of leaves. Snip off the bottom 2 sets of leaves – this part of the stem will be in the soil and roots will emerge from where the leaves were removed. Also snip off the top of the stem to include the top set of leaves. Your cutting will end up with only 2 sets of leaves. Immediately put the cutting in a good potting soil, making sure that the lower part of the stem where the 2 sets of leaves were removed is below the soil line. Keep the soil moist as the cutting develops a good root system.

You and the birds will enjoy this lovely shrub for years to come!