Putting the Garden to Bed

Now that fall has arrived and we have hit some very cold temperatures at night, it is time to clean up our gardens for the winter. Some things should be done this fall, but some can be left until spring. Here are a few things to do now to put your gardens to bed. 

Fall Pruning

Annual flowers can be cleaned up in fall because they die with a freeze. Perennials are best left standing until spring but some can be cleaned up now. It is nice to leave the plants over the winter for added interest and to provide food to birds. Plants such as roses and butterfly bushes that have hollow stems should be left standing and not pruned back until next spring. Precipitation can get into the hollow stems and freeze and thaw through the winter, which could crack the plant crown and lead to death. Leaving plants standing through winter will protect plants with hollow stems or with moderate hardiness to our zone. If you do chose to leave your perennial plants over the winter, be sure to wait until we are past our last spring frost before removing the plant material next spring, even if the plants green up underneath. The plant material does act as insulation and if removed too soon the plant will be more exposed to late winterkill. If removing plant material this fall, wait until it turns brown and replenish mulch to protect it over the winter. Mulch can be added up to 4-6 inches over the winter months, reduce back to 2-3 inches deep during the growing season.

People often think about pruning trees in fall. However, this isn’t the best time of the year to prune them. The optimum time for tree pruning is April, May, or June because at this time the tree can seal up the wound quickly while it is actively growing. If your tree needs to be pruned this fall, wait until the leaves have fallen from the tree to allow the tree to go completely dormant before pruning. If you are pruning an oak tree, the dormant period is the best time for pruning to avoid damage from oak wilt. Pruning evergreen shrubs is best done after they are fully dormant to avoid damage from winter injury. As for flowering shrubs, if it blooms in the spring, prune it after it blooms. If the shrub blooms in the summer, bloom in the late winter such as in February and March. 

Garden Cleanup

Now that our vegetable plants have died due to cold weather, it is time to clean up the garden. If any of your plants had disease or insect issues this summer, it is best to remove those plants and destroy them, don’t compost them. This will reduce the chance of seeing the problem again next year. Also, removing the plants from the garden at the end of the season will remove the overwintering site for insects found in the garden. Cleaning tomato cages and fences upon removal will also help remove the disease spores from the garden for next year.

After removing the plants, you may want to till your garden. If you plan to add fresh manure to your garden, that should be added in the fall rather than in the spring. So you can till your garden, add manure, and till it again to incorporate the manure into your garden soil for reduced compaction and improved organic matter content. If you till in the fall, add a layer of mulch to the garden to keep the soil from blowing off site during the winter. Grass clippings from a lawn that wasn’t treated with herbicides this year make a great mulch for the winter. You can till that back into the soil next spring before planting again.

Weather & Plants

 

The environment impacts our plants in many ways. We are always happy to see the shift in weather to help the heating and air conditioning costs of our homes. Plants are also very happy when the weather changes to a more comfortable temperature. Extremes for moisture and temperature can be very damaging to our plants on both ends of the spectrum. This year we have seen a wide range of these problems which are negatively impacting our plants. To say we have a “normal” growing environment or weather pattern in Nebraska is almost unheard of and this year was unlike any we have seen recently.

Floods

2015-06-04 18.32.28Typically we are excited to see rain throughout the season. However, when the rain doesn’t seem to end, like this spring and even again now, this can harm our plants. There is such a thing as overwatering plants. Plant roots need to breathe too, if they don’t have the oxygen they need they can start to develop root or crown rot that can kill the plant.

Besides problems with root growth and development, many fungal diseases have been popping up on our trees this summer. There are many leaf spots on our trees such as maples, oaks, pears, and crabapples as well as on our vegetable crops such as tomatoes, cucumbers, and others. The cool, rainy environment this spring led to the infection which is showing up now. Spraying so late in the season won’t really help. The best thing for these plants is to just keep them healthy through the season and then use sanitation in the fall to reduce the diseases next year. Destroy fallen leaves at the end of the season by raking them up and throwing them into the garbage and remove annual plants from the garden. Don’t compost infected plant parts because the spores may not be killed in a compost pile. Leaves left at the base of the plant or vegetable plants left in the garden will make a good location for the disease spores to overwinter and move back into the plant next spring.

Heat

Hot temperatures can be problematic for our plants, especially when that heat comes on fast after such a long, cool spring and winter. We have had problems with leaf scorch showing up on plants when we had that swing of temperatures into the 100’s with high humidity. This extreme heat is damaging to our plants, but especially this year when they were accustomed to cooler temperatures with more than enough water available to them. Scorch is still apparent on trees even though temperatures have cooled back off. For the survival and health of our plants through extreme heat, keep a 2-3 inch layer of mulch around the plants and keep them well watered when rains end in the summer.

Excessive cold

Excessive cold temperatures that we saw this winter can also harm our plants. The good thing for Southeast Nebraska was that we had snow cover most of the winter this year. If we had seen that much wind and cold temperatures without snow insulating the roots and crowns of our plants, we would have seen a lot more dieback.

Some of our plants did still have problems from the cold and some had problems from the high salt buildup around our plants from all the snow. Evergreen plants still transpire through the winter months. Desiccation happens when the moisture released from plants through transpiration exceeds moisture taken in through the roots. White pines see desiccation quite often in the winter months on the north side from the strong winter winds we see in Nebraska. This desiccation becomes even worse on plants that are in an area where snow with deicing salts are piled up each time we scoop snow.

There isn’t much to be done to fix trees now that desiccation has set in. For this coming winter, it would help to water the trees once a month on a warm day in the winter. You can also apply anti-desiccant products once every six weeks beginning after plants have completely hardened off, usually in late November. Continue applications through mid to late February. Avoid covering plants so heavily they become sticky with needles glued together. Have warm, soapy water nearby and clean out the sprayer immediately or equipment may be ruined by the product.

Think Ahead for a Fall Garden

Cold-Frame
Cold Frame Photo from Iowa State University Extension

It may seem that our gardening season finishes up as soon as it begins. This is the time, however, to start thinking about fall gardens and succession planting to extend your gardening season.

Start transplants indoors now

Fall gardening can be more beneficial than spring gardening. Some of our spring crops will actually grow better and produce better under cooler fall weather than they do in warmer spring temperatures. The weather often warms up quicker in the spring and can cause our spring crops to bolt or die early with little production. The longer, cooler fall season can be the answer to this problem.

The average first frost date for most of Southeast Nebraska is October 6-16, this comes from data from the High Plains Regional Climate Center. You can use the first frost date to figure out when to plant fall crops. Use the first frost date as a starting point, count backward the number of days to harvest listed on the packet of seeds and add a 10 day fall factor because the plants will mature slower due to the cooler weather. Plants or seeds should be planted in late July to early August.

Some of our fall plants could be started indoors now to get a transplant ready for fall planting season. Broccoli, cauliflower, brussels sprouts, cabbage, and others can be started indoors now so they are ready to be planted outdoors in late summer. Some of these cool season crops need 65-85 days to maturity and may do better if they are planted as transplants. Start them indoors now to be planted in mid-August to ensure harvest prior to heavy freeze.

Order transplants and garlic now to plant in September

Some local nurseries may not carry the transplants for your fall garden later into the season. A lot of the nurseries will clear out plant inventory by the later part of June and may not have these crops available in August for fall gardening. Check around to look for local inventory and see which nurseries will still carry these crops later in the season for fall planting. If you cannot find them locally, you can order seeds or transplants from mail order catalogs or through the online shopping options.

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Flickr image courtesy of Olga Filonenko per CC license.

Garlic is another crop that is planted in the fall, but it isn’t harvested in the fall. Plant garlic in October to be harvested the following June. Garlic needs to be planted in the fall because the new plants need to be exposed to cold soil temperatures for 1-2 months to form the bulb that will be harvested next summer. Even though it is early for planting garlic, you might want to order this early because garlic is difficult to find at planting time.

Plant second round of summer crops

Succession cropping, or double cropping can be done in our gardens as well. This is a gardening technique that allows a gardener to utilize a longer season of growth with multiple or the same crops. An early crop is grown, harvested, cleared off and a new one replaces that first crop. You can also do a staggered planting where you continually plant every week or 2 in the early season or plant an additional crop later in the season for longer harvest. Staggered planting can be helpful to avoid peak insect populations and avoid the majority of the damage on crops. Start your second crop in July if you haven’t already planted again.

Flood Recovery

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Photo of breached Levee in 2019 Flooding along the Missouri River, Photo by John Wilson, Nebraska Extension Educator

Many parts of Nebraska have faced flooding issues recently that have done a great deal of damage to homes and properties. Flooding has also caused damage to our landscapes and garden spaces.

Trees in the floods

Floods can do a lot of damage to our trees, depending on the length of time the trees were under water. According to the University of Wisconsin Extension, most plants can tolerate a few days of flooding during the growing season. Now that flood waters have or are receding take time to look at your tree and assess the damage.

When assessing the damage to your tree, make sure the roots remain at the same level in the soil and remove debris from around the tree roots. Hire an arborist to remove broken branches and check the stability of any leaning tree. If the tree is now leaning toward a building or other damaging location, have the tree removed. Do not fertilize your trees for at least a year to avoid further damage or disruption to re-establishing roots.

Garden space in the floods

Vegetable Gardens would be a concern due to food safety reasons. Floodwaters are not clean and they can carry bacteria and other harmful debris and pollutants with them as they move across the land. Fortunately, the floods came through before our gardens were planted, but there is still a concern with the soils and what crops we will plant. Spring garden crops and crops with edible parts coming into contact with previously flooded soils would be the most concerning.

According to John Porter, Urban Ag Program Coordinator for Nebraska Extension:

The recommendation depends on whether or not the crop comes in contact with the soil.  For crops that do not have direct contact with the soil, such as tomatoes, peppers, beans, etc. the waiting period between flooding and harvest should be at least 90 days. For crops that do have direct contact with the soil, such as lettuce and leafy greens, squash/pumpkins, and root crops such as potatoes and carrots the waiting period should be at least 120 days.  If the crops that don’t typically make contact with the soil are allowed to make contact, like tomatoes that aren’t staked, the 120 day recommendation should be followed.

Food safety concerns wouldn’t be present to gardens that were not affected by the floods. We can still plant our gardens into the soil during the 90 or 120 day waiting period, but any mature harvest should be discarded until after that waiting period for food safety. This means that we should opt out of spring gardening in areas where the floods impacted our vegetable garden spaces. Most of our summer crops would be fine, but you may want to use a trellis for cucumbers and use container gardening for things like zucchini to be on the safe side.

Turf in the floods

Lawns are resilient in flooded areas. It is best to stay off of wet lawns to avoid compacting the soil. Wait until it has dried out before mowing, driving equipment over, walking excessively over, and cleaning up the debris that may be on the lawn. Turfgrass can survive 4-6 days submerged, according to Missouri Extension. Most of our localized flooding receded quickly, so the lawn should survive. Also, because the flooding happened during the dormant period for the turf, the injury will be less than if it occurred during the warmer growing season. In areas that are still under water, when the floods do recede soil work, clean-up, and overseeding will be necessary. We may also see an increase in lawn diseases this summer due to the high amounts of rain and floodwater that affected them this spring. View this Turf iNfo on Turf Recovery after Historic Flooding for more information.

For more Flood Resources, visit: flood.unl.edu

 

Asparagus!

green-asparagus-pixabay

Spring officially began last week. That doesn’t mean we should get overly excited and go clean up our beds just yet, this winter has been long and cold so don’t get too ready for spring. However, Asparagus will soon be emerging from past years plantings and new plantings can soon be started.

Planting

Asparagus is a perennial vegetable that will come back every year providing you with more spears without having to plant it every year. Asparagus is planted as crowns in the spring as soon as the soil is dry and can be worked. This year we may have to wait a little longer before planting to give the soil time to dry out after all this snow and rain. Once planted, it is best to wait to harvest from the plant until the third year of growth. Light harvest can be done in the second year, but not all of the spears and not for a long period of time. Asparagus can be planted from seeds, but it will add one more year to the establishment period before harvest is initiated. It is best to give the roots time to become fully established before you begin harvesting. This allows the plant to grow better for a longer life.

Weed Control

Weeds are one of the most common problems for gardeners who grow asparagus. For years, many gardeners used the salt water from making ice cream around the asparagus. Asparagus is a salt tolerant plant and will survive if salt is placed around it and the weeds would die. However, asparagus will not thrive in a high salt condition and the salt can build up and cause asparagus to die over time. Also the salt content in the soil can create a crust which blocks water absorption into the plants which causes drought stress. It is not a recommended practice for weed control.

The better option for weed control in asparagus would be to use mulch around the plants. Any type of organic mulch will work for weed control around the asparagus including grass clippings, wood chips, straw, or hay. This organic mulch will keep the weeds down as well as hold onto moisture and add nutrients back into the soil as the mulch breaks down. Frequent, light shallow cultivation can be done early in the spring will help with weeds as well. Also, use preen that is labeled for use around the asparagus with the mulch to help with annual weeds.

Another tactic is to use a glyphosate product over the bed after the last harvest of the year. As long as the spears have all been cut off at the end of the growing portion of the season and there is no foliage or any green growth above the ground, the glyphosate will not harm the asparagus. Spray the glyphosate over the bed in the late spring when harvest is complete for the year. This will control the perennial weeds as well as the annuals. The spears will then grow back and not be harmed by the glyphosate. Follow up with preen and mulch to keep the weeds out.

Harvesting

Harvesting can be completed by cutting or snapping spears off of the plant as they emerge and grow to 5-8 inches in length. Either method of harvest is fine, I prefer to snap the spears to avoid spreading any disease problems with a knife that just harvested a diseased plant. Snapping is typically preferred by home gardeners. Harvest for 6-8 weeks or until the majority of the spears are less than 3/8 inches in diameter. When all the spears get spindly, the plant is running out of energy for production and harvest should be concluded to allow the plant to rebuild its resources for next year.

Understanding the Garden Catalog

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*Reference to commercial products or trade names is made with the understanding that no discrimination is intended of those not mentioned and no endorsement by University of Nebraska–Lincoln Extension is implied for those mentioned.

In the snowy winter we have seen this year, it is easy to become quite anxious for spring and the garden planting season. The seed catalogs are coming in almost daily still, which can help us plan for our gardens. However, some of the things listed in the catalogs are not always explained. Hopefully, this will help you with your garden planning.

Determinate vs Indeterminate

Tomatoes are one of my favorite vegetables to grow. They are taste so much better straight from my garden, they can be canned and stored in many different ways, and they are fairly easy to care for.

Tomatoes are available as Determinate or Indeterminate growth habit. Determinate tomatoes will grow to a specific size and produce only a certain amount of tomatoes through the season. While indeterminate tomatoes will continue to grow and produce until the frost kills them in the fall. Both types of tomatoes have their place.

Determinate tomatoes are better suited for container gardens or smaller gardens where it is not desirable for them to grow too large. Indeterminate tomatoes are great for gardeners who love to can, freeze, and eat a lot of tomatoes fresh. I prefer to use determinate varieties for the cherry or grape type of tomatoes so the plants don’t get so large and because I only use those for fresh eating. I use indeterminate tomatoes for my large, slicing tomatoes to use for salsa. Choose what works for you, but keep in mind the size and production differences between the two.

Heirloom

Heirloom varieties are also a point of confusion. Heirloom tomatoes are those that have been passed down for many generations. The seed can be saved and replanted from year to year because they are not hybrid plants. Heirloom tomatoes are often chosen because they have better taste than the modern hybrids, but they can have more problems with diseases and insects. Many gardeners choose hybrids now to combat disease issues that always plague tomatoes. Heirloom and hybrid tomatoes are both great choices, it just helps to know what you are purchasing when you buy the seed.

Other Seed Packet Considerations

The seed packet or description in the seed catalog can give you a lot more important information about the plants or seeds you are purchasing. Days to maturity is important so you purchase plants that will produce before the end of the growing season. Many of the tomato varieties are listed for 60 – 80 days to maturity, which means it will be 2-3 months after you plant them until they will begin to produce fruit. One variety, Fourth of July hybrid tomato, ripens after only 49 days. I planted this variety one year and it did start producing shortly after Independence day which I enjoyed so I could start eating my tomatoes that much earlier in the season.

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Space plants correctly from the beginning of the season

Also, be sure to pay close attention to the spacing listed on the seed packet or plant labels. It may seem odd to give such a small plant so much space in early May, but you will be happy you did later in the growing season. If plants are too close together, they may face more problems with diseases because they won’t have good airflow. Also, if you space your plants out more, mulching around the plants is much easier and garden access for harvest will be much easier.

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Correctly spaced plants allow for easier harvest and can be mulched between plants

Finally, don’t get too excited that you start your plants too soon. In southeast Nebraska, I suggest waiting until early May before you plant your garden. I like to use Mother’s Day as a good calendar date for planting vegetable gardens. Wait until after our frost free date, which averages April 24th but can be later. If you are planning to start your seeds indoors, you can start those in March. Don’t start too soon or your plants could get too leggy.

Planning Your Garden

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*Reference to commercial products or trade names is made with the understanding that no discrimination is intended of those not mentioned and no endorsement by University of Nebraska–Lincoln Extension is implied for those mentioned.

In January the seed catalogs begin to arrive in the mail. Each of these catalogs is a promise that spring will come again. In all the cold, snowy weather, I like the excitement of planning my garden for this year. When you are planning your garden, keep in mind things like sunlight, location, and water availability. Planning is important for the vegetable garden as well as for flowers, trees, and shrubs.

Planning a Vegetable Garden

It is always hard not to get overwhelmed with all the fun, new plants available to us. But when planning your garden, look at the location available first. If you are planning for a vegetable garden, you need to have at least 5 hours of sunlight per day but 8-10 hours per day is ideal for vegetables, preferably more sunlight in the afternoon. If you don’t have the correct sunlight, look for shade loving plants. The garden should be in a location that is fairly level and has good soil for best growth of the plants. Be sure to plant your garden near a water source to ensure the plants get watered sufficiently through the growing season.

Also, be sure to have the proper spacing allowed for your garden plants. We tend to plant vegetable plants too close together because they are small when we plant them. Remember to space them according to the label directions. If plants are too close together it can lead to more disease and insect problems when they grow too large and overlap one another.

black walnut, paul wray iowa state univ, bugwood
Black Walnuts Photo courtesy of Paul Wray, Iowa State University, Bugwood.org

Black Walnut Trees

Another important aspect of your garden to keep in mind, would be to keep your garden at least 50 feet away from Black Walnut trees. Black Walnut trees produce juglone, which is a type of plant produced toxin that works as a weed barrier around the tree. Juglone will hinder growth and sometimes kill many different types of plants. Tomatoes are very susceptible to juglone. There are also a lot of other trees, shrubs, and perennials that are susceptible to the juglone. If you are planting near a black walnut tree, be sure to check if your plant choices are tolerant of the juglone. If you are unsure about a nearby tree, bring a sample of the tree to your local Extension Office for identification and they can help you determine which plants will do well planted near your black walnut tree.

Mulch

Mulch is a necessity for your garden. Whether it is a vegetable garden, a perennial bed, or trees or shrubs, mulch is vital to help keep weeds down and to retain moisture around plants. Mulch can be either wood chips, straw, grass clippings, or another form of organic mulch. Inorganic mulches are not the best option due to the fact that it is very hot around the roots of plants and does not retain moisture. Make sure that your mulch layer is not too deep, keep it around 2-3 inches deep and keep it uniform around the tree, avoid mulch volcanoes.

Plant Size

Make sure you always read the growing requirements and full size of the plant before planting it in your landscape. It is most economical to plant things that fit in the space in your landscape, rather than pruning or removing it later. Often times, trying to keep a plant in a space that is too small for it will lead to death and costly removal fees. So it is best to start with a plant that will grow no larger than the space available to have a long-lasting plant for that area of your landscape.

Have fun when searching through your garden catalogs and find something fun and interesting to try. The 2019 Pantone Color of the Year is Coral, try to use that in your garden this year. Check out the All-American Selections for new varieties that have been tested in real garden settings, many of them were tested in Omaha and Lincoln with help from Nebraska Extension.