K-State Research and Extension

Q: The RCES Garden Project planted Butternut Squash this year and none of us know when it’s ready! For anyone who planted a winter squash plant, we can all learn something this week!
A: Harvesting Winter Squash Summer squash such as zucchini and scallop are harvested while immature but winter squash such as acorn, hubbard and butternut are harvested later, in the mature stage, after the rind is tough and seeds have developed. We normally think September is the time that winter squash are harvested. Harvesting too early leads to fruit that shrivels and rots. There are two main characteristics that help tell us when winter squash are mature: color and rind toughness. Winter squash change color as they become mature. Butternut changes from light beige to deep tan. Acorn is a deep green color but has a ground spot that changes from yellow to orange when ripe. Gray or orange is the mature color for hubbard. A hard, tough rind is another characteristic of mature winter squash. This is easily checked by trying to puncture the rind with your thumbnail or fingernail. If it easily penetrates the skin, the squash is not yet mature and will lose water through the skin — causing the fruit to dry and shrivel. Also, immature fruit will be of low quality. The stem should also be dry enough that excessive water doesn’t drip from the stem. Winter squash should be stored cool with elevated humidity. Ideal conditions would be 55 to 60 degrees F and 50 to 70 percent relative humidity. Under such conditions, acorn squash will usually last about 5 to 8 weeks, butternuts 2 to 3 months and hubbards 5 to 6 months.

Q: I would like to plant something for a fall harvest, but this is my first time thinking about a fall garden. Do you have any suggestions?
A: This is the time of year we normally think of planting a fall garden. Crops that can be planted now include lettuce, radishes, spinach, and similar crops. There still is time to raise another crop of green beans along with some summer squash. If you can find plants, cabbage, broccoli and cauliflower can also mature during the fall season.
Planting a fall garden is just like planting a spring garden with some big advantages. You will find the weed pressure to be much less and insect problems may be far fewer than in a spring garden. Seeds will germinate rapidly, so you will have crops up and growing in just a few days – compared to several weeks in the spring.
There are a few drawbacks to fall gardening, and one of those is that you must provide regular, frequent watering (possibly daily) until the crops are up and growing. It is best to plant seeds deeper than you do for a spring garden because soil is cooler and moister down a little deeper.
As far as soil preparation is concerned, don’t get too excited about deep tillage for a fall garden. Lightly work the soil enough to establish a seedbed; reserve your deep tillage for later in the fall. Also, don’t concentrate on adding a lot of organic matter and fertilizer for the fall garden. The organic matter can be added later in the fall with the deeper tillage, and excessive fertilizer application in hot weather is not a good idea. If you have some crop residue to remove from a previous crop, chop the residue with a lawn mower and lightly till the soil surface after the residue has had a chance to dry for 2 to 3 days.

Q: I recently read a report on the produce that contains the highest pesticide residuals, and many were fruits/vegetables that I consume on a regular basis. Should I be concerned?
A: The issue of pesticide residue in food is quite controversial. Pesticides are used because they have beneficial properties in terms of crop production and yield. Pesticides are used by farmers to prevent fungal invasion, insect damage, and the growth of unwanted (and often poisonous) plants. This has a positive benefit in terms of public health because fungi, insects, and non-crop plants can contaminate crops with many natural toxins.
Pesticides are probably one of the most regulated chemical products used in the U.S. The EPA, FDA and USDA are among the fourteen separate regulatory bodies that govern pesticide use. Despite the many regulations, pesticide residues are found in our food supply. Because residues are an inevitable by-product of pesticide use, many of the current regulations are in place to address the public health implications of pesticide use. Therefore, there are very strict restrictions on the amount of pesticides residues that are allowed in food.
One of the regulations that is currently in place requires that pesticide manufacturers conduct toxicity testing on the pesticide before it can be permitted for use on products either directly or indirectly destined for human consumption (this includes animal feed). This toxicity testing not only determines the health effects of pesticides, but also the level at which there are no toxic effects on the most sensitive population (i.e. children and the elderly). This ‘No Toxic Effect Level’ (NOEL) becomes the basis for the permitted residue limit. The regulations set the permitted residue level at a level that is from 10 to 100 times lower than the NOEL. Furthermore, if a pesticide is tested and a NOEL cannot be determined, then it is unlikely to be permitted for use on food crops. This helps ensure that if a person, child or adult, eats a larger than normal amounts of a particular food, or several different foods with the same or similar pesticide residue, they will still not reach the level of exposure required for a toxic effect to occur, even if they are more sensitive than the general population.
Each year, the Environmental Working Group publishes the “Dirty Dozen” report of foods that test positive for pesticide residues. While these foods may show pesticide residue is present, the risk is negligible. The Environmental Protection Agency (EPA) tolerance levels for pesticide residues is protective of human health. Test results are at levels well below tolerances set by the EPA. Drs. Carl Winter and Josh Katz of the Department of Food Science and Technology at the University of California-Davis are leading experts in the issue of pesticide residues. In a peer-reviewed, scientific article in the prestigious Journal of Toxicology (2011) they state the following conclusions: “Exposures to the most commonly detected pesticides on the twelve commodities pose negligible risks to consumers. Substitution of organic forms of the twelve commodities for conventional forms does not result in any appreciable reduction of consumer risks. The methods used by the environmental advocacy group to rank commodities with respect to (potential) pesticide risks lacks scientific credibility.” To read the full article, please visit the following link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3135239/.

Q: The leaves on my trees are starting to roll up tightly. I was told it is a watering issue, but I water my trees along with my grass every couple of days. What is the problem?
A: As a general rule, if you are watering both your trees and grass with the same pattern; one of them is being watered incorrectly.

Q: My neighbor has begun harvesting vegetables already and I don’t seem to have anything but blossoms yet. What’s going on?
A: If you have vegetables that are blooming but not setting fruit, you may have a problem with flower pollination. There are several possible reasons for this that usually vary by species. One condition that can affect several species at the same time is overfertilization. Too much nitrogen causes the plant to emphasize vegetative growth, often to the detriment of fruit production. Overfertilization can lead to a delay in flower production and a decrease in fruit set among the flowers produced. Tomatoes are very sensitive to this. If you have nice, large plants but no fruit, check your fertilization.
Squash, cucumbers, watermelon, and muskmelon can have a couple of other problems. First, the early flowers on these plants are usually all male. The production of both male and female flowers becomes more balanced as time passes. You can easily tell the difference between the two because only the female flower has a tiny fruit behind the blossom. If you have both, have not overfertilized. You still have a problem, so make sure you have pollinators. Look for the presence of bees visiting the plants. If you don’t see any, try hand-pollinating several flowers. Use a painter’s brush to transfer pollen from the anther of the male flower to the stigma of the female flower. If you get fruit on only those flowers you pollinated, you need more pollinators.
Make sure you aren’t killing the pollinators with overuse of insecticides. Tomatoes are wind pollinated and therefore not dependent on pollinators. Another possible problem is temperature. Tomatoes normally won’t set if the night temperature is below 50 due to sparse pollen production. This, of course, is only a problem early in the season. However, they also won’t set when nighttime temperatures are above 75 degrees F and daytime temperatures are above 95 degrees F with dry, hot winds.

Q: I was told to add nitrogen to my annual flowers to make them bloom better. Is this true?
A: Modern annual flowers have been bred to flower early and over a long period of time. They are not as easily thrown off flowering by high nitrogen levels as vegetables are. As a matter of fact, providing nitrogen through the growing season (sidedressing) can help maintain an effective flower display for warm-season flowers. Apply a high nitrogen sidedressing four to six weeks after flowers have been set out. Additional fertilizations every three to four weeks can be helpful during a rainy summer, or if flower beds are irrigated. Common sources of nitrogen-only fertilizers include nitrate of soda, urea, and ammonium sulfate. Blood meal is an organic fertilizer that contains primarily, but not exclusively, nitrogen. Use only one of the listed fertilizers and apply at the rate given below. Nitrate of soda (16-0-0): Apply 1/3 pound (.75 cup) fertilizer per 100 square feet. Blood Meal (12-1.5-.6): Apply 7 ounces (7/8 cup) fertilizer per 100 square feet. Urea (46-0-0): Apply 2 ounces (1/4 cup) fertilizer per 100 square feet. Ammonium Sulfate (21-0-0): Apply 4 ounces (½ cup) fertilizer per 100 square feet. If you cannot find the above materials, you can use a lawn fertilizer that is about 30 percent nitrogen (nitrogen is the first number in the set of three) and apply it at the rate of 3 ounces (3/8 cup) per 100 square feet. Do not use a fertilizer that contains a weed killer or weed preventer.

Q: We have been getting more rain lately than we are used to, what potential effects is all the standing water having?
A: Waterlogged soils push out oxygen that roots need to survive. Some plants have mechanisms to provide oxygen to the roots even under saturated conditions but most of our vegetables and flowers do not. The longer these plants are subjected to saturated soils, the more likely damage will occur. Usually, as long as water drains away within 24 hours, the impact on plant health is minimal. However, shallow, stagnant water under hot, sunny conditions can literally cook plants, reducing survival time to as little as a few hours.

In regards to the safety of eating produce from a garden that has been flooded, standing water should not cause a safety problem as long as the aboveground portions of the plant remain healthy. Do not use produce from plants that have yellowed. Also, using produce flooded with water contaminated with sewage (lagoon) or animal manure can also be dangerous. The safest approach is to discard all garden crops that have been in contact with such water. Certainly, leafy vegetables should always be discarded. However, you may eat fruit from such crops as tomatoes, peppers, eggplants, sweet corn, squash, cucumbers, and similar vegetables that develops after the waters have subsided as long as the fruit is not cracked or soft. Always wash vegetables thoroughly before eating.

Under the cool conditions of early spring, turfgrasses can often survive several days of flooding. However, during hot, sunny conditions with shallow, stagnant water, lawns may be damaged quickly. This situation often occurs when shallow depressions in a lawn allow water to pool. Note such areas and fill in with additional soil once the waters have subsided. Trees differ markedly in their ability to withstand flooding. Some trees have mechanisms in place to provide oxygen to the roots of plants with water saturated soils and others do not. However, most trees will maintain health if flood waters recede in 7 days or less. It also helps if water is flowing rather than stagnant as flowing water contains more oxygen. If the roots of sensitive trees are flooded for long periods of time, damage will occur including leaf drop, iron chlorosis, leaf curl, branch dieback, and in some cases, tree death. Try to avoid any additional stress to the trees this growing season. Ironically, one of the most important practices is to water trees if the weather turns dry. Flooding damages roots and therefore the root system is less efficient in making use of available soil water. Timely waterings are vital to a tree’s recovery.

Soils often become compacted and crusted after a heavy rainfall. This also can restrict oxygen to the roots. Lightly scraping the soil to break this crust will help maintain a healthy root system and therefore, a healthy plant. Be careful not to cultivate too deeply as shallow roots may be damaged. If you think the excessively wet weather will continue, bedding up the rows before planting even just a couple of inches, will improve drainage and allow for better aeration.

Q: Rabbits seem to be eating my freshly planted garden as fast as I can get it in the ground. What can I do?
A: Rabbits in gardens are a perennial problem because of the wide variety of plants they can feed on. This time of year, they gravitate to young vegetables and flowers. But there are some vegetables that are rarely bothered including potatoes, tomatoes, corn, squash, cucumbers, and some peppers. The question is how do you protect other, more susceptible plants? Fencing provides a quick and effective control method. The fence does not need to be tall; 2 feet is sufficient for cottontails. But the mesh must be sufficiently fine (1 inch or less) so young rabbits will not be able to go through it. Support for the fence can be supplied by a number of products, but electric fence posts work well.
Often fencing is not an acceptable choice because it affects the attractiveness of the garden. Other ways to control rabbits including repellents, trapping and shooting. Repellents are often suggested for control but often do not last long and require frequent reapplication. Also, many are poisonous and cannot be used on plants or plant parts destined for human consumption. Live traps can be used to collect and move the rabbits to a rural area several miles from where they were trapped. A number of baits can be used to entice the rabbit to enter the trap including a tightly rolled cabbage leaf held together with a toothpick. However, rabbits often avoid baits if other attractive food is available.
Another possibility is to use a motion-activated sprinkler. These are attached to a garden hose and release a short burst of water when motion is detected. Contech, Orbit and Havahart are suppliers and each is advertised as protecting up to at least 1,000 square feet. Shooting is another possibility when it is safe and legal to do so.