Garden Talk

with Rebecca Jordi

Leave a comment

Q: Will you please identify this weed for me?

Brazilian Pusley

Brazilian Pusley

A:  Thanks for bringing me a sample to the plant clinic.  The weed is called Brazilian pusley, Richardia brasiliensis. Brazil Pusley is an annual or perennial and looks similar to Florida pusley except it has a very deep, thick root. The thick root may be an excellent place for nematodes to live. Brazilian pusley has a cluster of small white flowers at the top.  In Florida, this plant occurs throughout the state on disturbed sites and roadsides, and in pastures and lawns. It is distributed in the southeastern United States, from southern Texas along the coastal plain to southeastern Virginia. This weed will bloom in almost any month that lacks frost.


Leave a comment

Q: Some of the University of Florida publications on lawn grasses talk about vertical mowing. What is vertical mowing?

Verticle MowerA:  The typical lawn mowers used in the home landscape are called rotary as the blades move in a horizontal plane.  Vertical mowers have blades which move in a vertical (up/down) plane. This type of mower can be used to remove thatch buildup in lawns.  If the thatch layer exceeds 1 inch, it can be removed by vertical mowing, or “verticutting,” in early spring to midsummer. It is a messy process and it is difficult for most homeowners to perform properly.  Verticutting uses vertical blades which slice through the thatch and slightly into the soil, resulting in large portions of the dead material being removed from the top of the lawn. Usually the blades are spaced about three inches apart which works best for St. Augustinegrass. This type of mowing can cause severe damage to the grass and requires a period of recuperation therefore it is best done when the grass is actively growing. Verticutting should be done in one direction only – not in cross sections.  Verticutting will pull out large amounts of grass and thatch which will require cleaning and removal.  It will be important to mow the grass directly after verticutting but be sure to mow at the highest height – never scalp or cut the lawn too short.  Water the dethatched lawn immediately to avoid dehydration of any exposed roots.  One week after vertical mowing, you can apply 15-0-15 fertilizer at the rate of 1 pound of nitrogen per 1000 square feet to encourage recovery. Water the fertilizer in immediately to prevent burning the grass. Periodic topdressing (adding a uniform layer of soil or sand on top of the grass) with ¼ inch of soil matching the current soil is the best method to alleviate thatch accumulation. If topdressing, be sure to use soil free of weed seeds and nematodes and be careful not to exceed recommended topdressing rates.  Adding  too much soil or organic matter will encourages large (brown) patch disease.

Leave a comment

Q: I found these pea pods growing on a vine in my back yard. Can I eat them?

American Groundnut

Native American Groundnut

A:  I am checking with the University of Florida’s Herbarium for a positive identification as I have only seen this vine once before at Egan’s Creek. The flower cluster is lovely; slightly larger than a golf ball in shades of magenta, pink, rusty brown and white. The vine has the leaf configuration similar to wisteria. Kathy Russell, City of Fernandina Parks and Recreation, steered me towards the Native American groundnut, Apios americana, and I am inclined to agree with her. This vine can grow in partial shade or full sun; prefers low and moist woods, thickets, stream and riverbanks, ponds, marshes, meadows, and wet ravines. It is a scary thing to eat plant material from the wild but in this instance, if it is truly the groundnut, then the seeds and tubers are edible. Most of the information I have found on this plant has come from a publication by James Duke from Purdue University. According to his paper during the potato famine of 1845, Apios was introduced to Europe. Its cultivation there as a food crop was abandoned when growing potatoes again became feasible. The tuber is more slender and somewhat smaller than the typical potato as it is about 2.5 inches long.  However, the tubers often grow in clusters of two to four.  American groundnut was prized by early American settlers who ate them boiled, fried, or roasted. They called them groundnuts, potato beans or Indian potatoes. The Pilgrims of New England survived their first few winters by living on them. I don’t know about you but that tidbit of information was news to me. Even bread was made from the root. Indians were said to eat the seeds like lentils. American groundnut is found growing from eastern Canada and the US. It grows from Florida to Texas, north to Nova Scotia and west to Minnesota and Colorado. Like so many other vines, this species can also be “weedy” and cause problems in cultivated areas. It has been known to be a serious weed in cranberry plots (Devlin, 1981). Fernald (1958) recounted an anecdote indicating the economic value of the groundnuts to the pilgrims, “The great value to the colonists of this ready food is further indicated by a reputed town law, which in 1654 ordered that, if an Indian dug Groundnuts on English land, he was to be set in stocks, and for a second offence, to be whipped.”

Leave a comment

We were thinking about planting a tree to be used as a permanent Christmas tree for our yard. We noticed you have two in the demonstration garden, the Southern Redcedar and the Arizona cypress. Which of those two do you think would be a better choice?


Southern Red Cedar

Good question.  Both are evergreen and have the Christmas tree (pyramid) shape and they both would make a nice addition to any landscape if you have enough room.  Southern Redcedar, Juniperus silicicola, can grow to 40 feet tall with a 25 feet spread. It tolerates most any kind of soil and light conditions – full sun to light shade. Southern Redcedar is very drought and salt tolerant.  It has very few insect issues but there are a few fungal diseases which can cause twig die back of leaf galls.  Most of the diseases can easily be pruned out and controlled without chemical applications.  Arizona cypress, Cupressus arizonica var. arizonica grows to the same height and spread as the Southern Redcedar, likes similar planting conditions although we are not sure about its tolerance for salt spray.  Arizona cypress has a slight bluish cast to the leaves especially on new growth. It has no real insect enemies but has been known to develop blight in cool, humid conditions as well as stem canker.  One big difference, Southern Redcedar is native and has been known to attract birds while Arizona cypress does not.  I don’t think you could make a mistake by planting either one but I like the idea of having a native tree in my yard which is able to supply food for birds.  But don’t let me influence your final decision!

Southern Redcedar:

Arizona Cypress:

Leave a comment

I have been reading about the benefits of eating sweet potatoes and I think I would like to grow it here. What do you recommend?

Sweet_potatoThe sweet potato, Ipomoea batatas, originated in tropical America and ranked second only to the Irish potato as an important vegetable until World War II. The sweet potato is a good source of sugars, carbohydrates, calcium, iron, and other minerals and vitamins, particularly A and C. The edible part of the sweet potato is a swollen storage root. The common sweet potato requires a great deal of garden space because it produces long vines.  However, there is a cultivar (‘Porto Rico’) which can be more bush or bunch-like and these can be grown in containers. Container grown sweet potatoes will require additional care such as watering and fertilizing but for those of us with limited sunny spaces, bush sweet potatoes are a viable option.  Sweet potatoes need warm days and nights so they are considered a warm season vegetable here. The soil pH should be between 5.6 and 6.5, typical of most vegetables.  If the soil pH goes near or above 7, the plants will be more prone to diseases.  In Northeast Florida, we recommend planting sweet potato between March and June; it will take about 120 – 140 days to mature for harvesting. Sweet potatoes are grown from slips (transplants) and it is critical for home gardeners to purchase disease-free plants from reputable growers or garden supply stores. Like most vegetables, it is wise to rotate crops and avoid planting the same vegetable in the identical spot repeatedly. If you grow them in containers, then we would suggest you replace the soil each year.  Consider applying ½ your normal fertilizer amounts to the soil 10-14 days prior to planting and mix it well into the soil.  The other ½ of the fertilizer can be applied along the sides of the mound (side-dressing) after the plants become established or show evidence of new growth.  If you plant the bush variety in containers then incorporate the fertilizer into the top few inches of the soil – do this manually (by hand) to avoid damaging tender roots. There is another tropical sweet potato, often called the Cuban sweet potato, which can be grown here too.  It has white flesh rather than the common orange or yellow flesh we are accustomed to seeing in the grocery stores and in our candied sweet potato recipes during the holidays.  Attached is a complete publication from the University of Florida on the Cuban sweet potato: