September 23rd will be the autumn equinox which means that in about 10 days we will have equal daylight and darkness. Since mirlitons (chayote) are photoperiodic (flowering triggered by equal light), we should start to see some flowering soon. Mirlitons are also thermoperiodic which means a little cool weather will also stimulate flowering. Here are a few things to keep in mind for the fall crop:
1. Don’t fertilize during this period. Mirlitons require additional nitrogen when they first start and throughout the vining stage, but they produce more fruit in the fall if they have less available nitrogen. This is always one of the tricky things about mirlitons–they have different nitrogen requirements at different times. This is a challenge for growers using manure since it is slow release, but the slow release fertilizers, natural or synthetic, are a good way to avoid excessive nitrogen.
2. Watch for leaf footed bugs ( a variety of stink bugs). There are photos of them on the web page photo site. Immature leaf footed bugs are red and easy to identify. I have seen that they will feed on flowers and fruit–leaving the fruit with late bruising and a bitter taste. They are easily treated with organic pesticides or just manually picked off. Various beetles can cause damage to leaves and stems and introduce wilt and other diseases and they can also be treated. In many ways, the traditional overhead trellis makes it difficult to detect and treat insects, so there is an argument for a lower trellis. In addition, a 4-5 foot trellis permits for easier hand-pollination and the trellis can be more easily covered with plastic to protect from cold temperatures.
3. When is a mirliton ripe? Most fruit will mature within 21 days of flower germination, and the “thumbnail test” is the easiest way to test for maturity. Simply press youth thumbnail into the flesh and if it dents the flesh easily, the fruit is immature and still contains too much moisture and not enough structure. I mature mirliton will be hard and resist denting. Some growers like larger mirlitons (the average at picking, depending on the variety, is 8-12 ounces). You can leave the fruit on the vine for several weeks and some heirloom varieties will get very large–up to 30 ounces. Other varieties have a terminal fruit growth of about 10 ounces. The older the mirliton, the more fibrous the flesh. Again, it is a matter of taste and you can experiment with picking and boiling at different sizes.
5. Pollination. Bees are the primary pollinators for mirlitons. Bees are finicky and systematic feeders and simply having them in your garden does not mean they will pollinate your plant. Go out about 10:00 a.m. on a sunny day and see if they are visiting your mirliton flowers. If they are not, you have to hand-pollinate per the instructions on the photo site or you can spray with Fruit Boost or other artificial queen bee hormones. Only one pollination is necessary since the pollen is sticky and adheres to the female stigma. Mirlitons will flower from October through December if the weather is warm, but hormone levels drop off after November so germination rates are lower.
6. Protect from cold weather. You can take your chances with cold weather, but immature fruit will die when temperatures drop below 55 degrees F. If you want your mirlitons to survive cool weather damage or frost damage, invest in a large roll of plastic, a drop light, and a receptacle thermostat (see growers guide). By covering your vine and keeping the temperature above 60 degrees, you will protect the new fruit and be able to harvest all the way through December. You may have to removed the plastic during the day to prevent overheating. Freeze damaged fruit cannot be eaten but they do grow well as seeds if they are planted immediately on containers or mounds.
7. In the growers guide, we suggest several methods of overwintering sprouts. Leo Jones of Marrero, Louisiana told me of good technique of overwintering sprouts if you don’t have container room. He digs a hole in the garden and fill it with straw and places several mirlitons in the hole and covers with soil and mulches. He digs these up in march and they have developed a good root structure and shoot and can be transplanted to mounds (bury the roots and shoot completely to avoid sun scorching. If you are going to store mirlitons in paper bags (the old fashioned way, which we don’t recommend), follow the instructions in the growers and powder the fruit in sulfur to protect them from fungi.
8. As always, send us photos of your plants. We are always looking for different heirloom varieties, so feel free to email us about growers in your area. This last summer we had an anthracnose epidemic which damaged many of the vines in the Southern part of the state, but rest of the state had low rainfall so we expect a good crop of heirloom mirliton seeds. If you are subscribed to the “Alerts” on the web site, you will be notified when seed is available through cooperating garden centers or directly from growers. It is always advisable to start with 3-5 sprouts to increase your chances of getting a plant through the first year, which is the key to a healthy and productive vine. Second-year plants have better root structure and “systemic acquired resistance” means that plants exposed to fungal toxins like anthracnose will develop some natural resistance to the fungus in future years.
Lance Hill
Mirliton.org