Lavender, other herbs can be tricky to grow from seed
Q: In March I bought some lavender seeds and could never get them to sprout. Do you have any tips for me about how to grow container lavender? I am in Hot Springs.
A: Some gardeners are a whiz at producing transplants from seeds, but I tend to buy herb transplants rather than starting new plants from seed. That being said, since you already have seeds, why not try again. Lavender can be directly sown in the ground where you want it to grow from late April to early June, or start it indoors. Lightly cover with soil—don’t plant them too deep. Keep the soil moist but not wet. I find an easy trick is to put them in a pot and have the soil about ½ inch below the pot edge. Then cover the top of the pot with plastic wrap or use a baggie over the pot to hold moisture in. I have a friend who uses the clear shower caps she saves from hotels. It can take 2 to 3 weeks before you see the seedlings emerging. The soil temperature needs to be kept in the 70s. They do sell heat mats for seed germination, much like a heating pad for us. Once the seedlings emerge, make sure there is room for them to grow under the covering. It can take 2-3 months for a seedling to be large enough for transplanting outdoors. Then it can be another year or two before it is old enough to start blooming. Now, do you see why I buy plants? I will also warn you that lavender can be a bit finicky in a southern garden. Make sure it is in very well-drained soil and don’t over-water it. I have had luck in containers and in rocky, poor soil.
Lavender is not a huge fan of heat and humidity, but I have one plant that is now starting its fourth year.
Ornamental sweet potatoes edible, but maybe not tasty
Q: I just had a hard freeze at my house last week and left a lot of my summer plants. We started cleaning up right after the frost and I found what looks like real sweet potatoes under my ornamental sweet potato vines. Can I eat them?
A: The long growing season this year was a blessing that kept us summer way longer than normal. Even in a shorter season we see “sweet potatoes” under the ornamental annuals. The ornamental sweet potatoes were discovered in a breeding program for edible sweet potatoes. While they are technically edible, the quality and/or production levels were not good enough for the fresh market, so they marketed them as an ornamental. Eating them won’t hurt you, but the taste might not be to your liking. You can also save the sweet potato to start new plants for next spring. Some breed true—keeping the bright green foliage or black, depending on variety, while others have reverted to the old green. It is worth trying.
A little ash goes a long way in a garden plot
Q: In our town in Arkansas leaf burning is allowed unless we are in a drought, which luckily, we are not in this year. I burn leaves regularly and I also have a wood burning stove. Can I use some of these ashes on my flower beds and on my garden plot? If so, how much would be advisable?
A: A little bit goes a long way. Wood ashes tend to raise the pH of the soil, so don’t use them around acid-loving plants and don’t add additional applications of lime to the soil if you are using them. Ash also contains salt, so large amounts would not be beneficial to a garden. Composting the ashes along with leaves and other raw materials can help to dissipate the salt issues for later use, but have it tested to determine pH before using. When using wood ash, a light layer is all that is needed. Avoid using ashes around azaleas, blueberries and other acidic lovers, and don’t use it in your vegetable garden where you grow potatoes, or you may have potato scab—which occurs when you raise the pH.
Give indoor lemon trees light to keep them healthy
Q: I found a great deal on some Meyer’s lemon trees this fall. I repotted them into larger pots, and have fed them and moved them indoors. Both trees bloomed a month or so ago and have put on many lemons. My problem is that one tree has a number of leaves turning yellow. Is this a result of fertilizer or something else? Would you recom
mend a different fertilizer, and do you have any hints for carrying them through the winter? Another question is should I remove some of the new small lemons to allow the tree to produce larger fruit.
A: Arkansas is never going to compete with Florida or California for the lemon market, but there are some nice fruiting varieties that will do well in Arkansas as long as they get winter protection indoors. Yellowing of leaves now could be a result of the move indoors—less humidity, less light and a more constant temperature. The later they move inside, the more stress they go through getting acclimated. They may also be yellowing because of the heavy fruit load. Fruit trees typically push their energy more into the fruit than the foliage when there is fruit on the plants. Thinning is a practice that will lead to larger but less fruits — your call. Do you want a lot of smaller fruits or a few large ones? To help them inside, group the plants together in a very sunny location. If you don’t have ample light, consider supplementing with artificial light. Water as needed and because of the fruit set, fertilize every three weeks with a water-soluble fertilizer until the fruit is harvested. Then let them rest a bit. You will probably see them start flowering again in later winter before you move them back outdoors.
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@