In the Garden with Janet B. Carson

IN THE GARDEN: Trifoliate orange fruit is bitter but edible

Q What is this and is it edible? I found it growing on a short, thorny tree. We live near Rogers.

Trifoliate orange is a hardy, thorny, fruit-bearing tree that grows statewide and tends to colonize its area. (Special to the Democrat-Gazette/JANET B. CARSON)
Trifoliate orange is a hardy, thorny, fruit-bearing tree that grows statewide and tends to colonize its area. (Special to the Democrat-Gazette/JANET B. CARSON)

A The fruit in question comes from the trifoliate orange tree (Poncirus trifoliata). This citrus relative is native to China and does produce edible fruits, but they can be pretty bitter, and as you can see, are loaded with seeds. Some people do make lemonade with them or sauces. The leaves have three lobes, thus the trifoliata species name. The tree is covered in thorns. It is hardy statewide, but it can colonize or spread, so pay attention if you have one in the yard. It is not gardener-friendly with all those thorns, but it does produce fragrant white blooms in the spring, followed by these fruits which turn yellow in the fall.

Crape myrtles can develop powdery mildew. (Special to the Democrat-Gazette/JANET B. CARSON)
Crape myrtles can develop powdery mildew. (Special to the Democrat-Gazette/JANET B. CARSON)

Q Is there a systemic fungicide for powdery mildew on crape myrtles? Also, where can I buy two copies of your book In the Garden?

A There are several fungicides that help manage powdery mildew on crape myrtles. I assume when you ask for a systemic product you are planning to use it to prevent powdery mildew, similar to the products we use for scale insects. The mode of action for a systemic pesticide is that it is applied and taken up by the plant and works from the inside of the plant. While there are systemic insecticides that allow you to use one application for a whole season of protection, there isn't a similar fungicide. There are systemic fungicides, but they would need to be

reapplied periodically for all-season coverage. If you have powdery mildew every year on your crape myrtles, then preventive sprays could be necessary — applying before you see the disease, not trying to cure it once you have it. Here is a link to a fact sheet from plant pathologist Sherrie Smith with more information: arkansasonline.com/126mildew. I have two books, In the Garden, a general year-round gardening guide published in 2010, and Field to Feast, which focuses more on edibles and was published in 2016. Both books can be ordered from the Arkansas Democrat-Gazette store (arkansasonline.com/126books). In Little Rock, the Crown Shop carries the first book, and the Historic Arkansas Museum usually carries both.

Field to Feast by Janet Carson
Field to Feast by Janet Carson
It's wise to delay planting spring-blooming bulbs until weather cools off in mid-October. (Special to the Democrat-Gazette/JANET B. CARSON)
It's wise to delay planting spring-blooming bulbs until weather cools off in mid-October. (Special to the Democrat-Gazette/JANET B. CARSON)

Q Given this year's extended hot weather, what timing do you recommend for putting spring-flowering bulbs in the ground?

A I never recommend planting spring-blooming bulbs until mid-October through December. We are finally cooling off, and you can begin to plant.

Foliage of spent canna lilies can harbor a pest if left in place all winter. (Special to the Democrat-Gazette)
Foliage of spent canna lilies can harbor a pest if left in place all winter. (Special to the Democrat-Gazette)

Q I've planted a few cannas like we used to have when I was a boy. Is it best to let the dead foliage remain on top of them for the winter, more or less as a mulch until spring, or should I go ahead and remove it once the foliage is frozen back later this fall?

A Definitely remove the foliage once it dies back. A common pest of cannas is the canna leaf roller, which can live overwinter in spent debris. Cut and remove the foliage and then add a little fresh mulch after cleanup.

Some varieties of Onethera, or evening primrose, can spread aggressively. (Special to the Democrat-Gazette/JANET B. CARSON)
Some varieties of Onethera, or evening primrose, can spread aggressively. (Special to the Democrat-Gazette/JANET B. CARSON)

Q A friend and fellow fan of yours suggested I write you to help me identify this plant. It's a volunteer, about 3 1/2 feet tall, not especially attractive but certainly interesting. There are numerous buds that look like they will bloom but also many down the stem that look like they already have bloomed. I don't think I missed a bunch of yellow flowers, but maybe I did! This bed is mostly azaleas and gardenias but the same friend brought me a variety of plants from her garden before a recent move, so I didn't know if this was one of hers until recently when I sent her a photo to identify. She's stumped too. Any help is appreciated.

A While I can't get a good view of the flower, I think it looks like an Oenothera or evening primrose. There are several species, and some can spread a bit aggressively, so keep an eye on it.

Retired after 38 years with the University of Arkansas Cooperative Extension Service, Janet Carson ranks among Arkansas' best known horticulture experts. Her blog is at arkansasonline.com/planitjanet. Write to her at P.O. Box 2221, Little Rock, AR 72203 or email

jcarson@arkansasonline.com

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