University of Minnesota West Central Research and Outreach Center, Morris Vegetable Gardening 301
Vegetable Gardening 301 Topic Areas Practices that support the development of healthy, vigorous root systems Maximizing your space with succession planting Growing fall crops How to successfully grow tomatoes, onions, carrots, peas and melons
Healthy Soils, Healthy Plants Healthy People Cultural practices that help maintain fertile soil: Soil testing Crop rotation Growing cover crops Manure as a valuable nutrient source Composting Applying supplemental fertilizers Maintaining Soil Fertility: Cultural practices that support the development of healthy, vigorous root systems result in efficient use of available nutrients
Gardening Problems caused by Poor Soil Quality Symptoms of poor soil quality include the following: The soil is dried and cracked in summer Digging holes in the soil is difficult, whether it is wet or dry Plants wilt in hot weather, even with added water Tomatoes and peppers get blossom-end rot which is a calcium imbalance but related to poor developed root system Water tends to pool on the soil surface and to drain slowly, or it runs off the surface
Garden Soil Organic matter keeps the soil loose and healthy Improves the ability of the soil to accept and store water More water goes into the soil, and less water runs off the surface or possibly into nearby rivers and lakes Amending your soil may reduce the amount of water a garden requires
Common Organic Amendments Leaves are perhaps the best and most readily available organic matter source for vegetable gardens Cover crops provide a easy way to add organic matter to soil Both winter and summer cover crops can be used You can dig in the cover crop before planting your garden Manures and manure composts have high nitrogen, ammonia or salt content or high ph (above 8) In general, it is best to avoid manure and manure composts at high-rate applications Use manures in small amounts to replace nitrogenphosphorus-potassium fertilizers
When is Soil Ready Soil should not be worked when too wet Main reason for this lies in the precious air space in your soil When it s wet your footsteps, hands and digging will squish out that air space-leaving no room for roots to spread and grow Compacted soils tend to drain more slowly Soil is fragile. If you treat it right you will be rewarded with healthy crops Cultural practices that support the development of healthy, vigorous root systems result in efficient use of available nutrients
Incorporating organic matter into soil Most common methods involve digging or rototilling Excessive rototilling has detrimental effects on soil structure, particularly when the soil is wet Disturb the soil as little as possible to keep the beneficial fungus and natural soil structure intact Rototilling can compact soil just below the tillage depth, reduce the volume of pore spaces in soil for air and water, and kill earthworms Digging amendments into the soil is hard work but will enable you to incorporate as deeply as you choose to dig
Soil Testing Getting a soil test will help you determine deficiencies U of MN Soil Testing Lab Never good to add amendments without knowing what the soil lacks Quality of your test results depends largely on the quality of your sample Soil samples may be collected whenever soil conditions permit If your garden has large areas which differ in fertility, take one sample from each area
Soil Testing Use a garden trowel (#2) or sampling tube (#1) Scrape away or discard any surface mat of grass or litter Place the soil sample in a clean bucket Repeat sampling in several random locations within the chosen area. Mix soil well to make one sample For the regular test cost is $17.00 http://soiltest.cfans.umn.edu/test ing-services/lawn-garden
Crop Rotations Crop rotation is deciding which crop to plant where from one year to the next Rotation will help manage soil fertility and help avoid or reduce problems with soilborne diseases and insects Each crop has different nutrient requirements, and will affect soil balance differently For Example Problem: If you plant sweet corn in the same spot year after year, that area will run low on nitrogen and phosphorus Solution: Change the location of sweet corn each year. You'll be able to renew the plot where it grew the preceding year, so your soil won't be out of balance
Crop Rotations Leafy/fruiting crops use up nitrogen quickly such as lettuce, cabbage, and tomatoes Root vegetables are light feeders Peas, beans, and other legumes add nitrogen to the soil but need lots of phosphorus Maintain balance of soil nutrients by not planting the same category of crop (leafy/fruiting root, and legume) successively in the same place It's best to follow nitrogen-fixing legumes such as peas or beans with nitrogen-loving leaf or fruiting crops such as lettuce or tomatoes Follow the heavy feeding crops with light-feeding root crops
Growing Cover Crops Cover crops are sown thickly to form a living mulch Keep weeds in check Mow the plants down prior to flower to prevent them from selfseeding and becoming weeds themselves Turned into the soil to provide organic matter and nutrients Include vetch, clover, beans, peas, annual ryegrass, oats, rapeseed, winter wheat, winter rye and buckwheat Plant in the early season: turn it under and plant warm-season vegetables Or, after early-maturing vegetables have been harvested, plant a cover crop Turn in the dead plant material after a killing frost in late fall
Nitrogen Fixing Plants Many plants in the legume family, such as peas, beans, vetch and clover, grow in cooperation with soil-dwelling bacteria Bacteria live in nodules on the roots of legumes They fix atmospheric nitrogen gas from the air and convert it to a form plants can use Legume dies and its roots begin to decompose, nitrogen in the nodules becomes available to other plants when plants are tilled under
Drip Irrigation
Advantages of Drip Irrigation May require less than half of the water needed for sprinkler irrigation Disease pressure may be less because plant foliage remains dry Extensive automation is possible Water applications are made directly to the plant root zone. No applications are made between rows resulting in better weed control Harvesting, can continue during irrigation because the areas between rows remain dry Fertilizers can be applied efficiently through the drip system Compared to sprinkler irrigation, soil erosion can be reduced
Disadvantages and Limitations of Drip Irrigation Initial investment costs may be higher than those of other irrigation options Rodent, insect, and human damage to drip lines are potential sources of leaks Water filtration is necessary to prevent clogging of the small emitter holes Compared to sprinkler irrigation, water distribution in the soil is restricted
Succession Planting A way to extend your harvest by staggering plantings of crops or planting varieties with staggered maturing dates Good succession plan means fresh food from spring until late fall Before planting create a detailed succession plan of what and when to plant Develop an understanding of their individual growth habits and preferences
Succession Planting Sow small amounts of seed at regular intervals For instance, sowing small rows of leafy greens weekly, ensures a consistent supply for salads rather than a big surplus all at once Planting at the same time with varieties that mature at different times, such as early, middle, and late-ripening corn, is another way to extend the harvest time of a single crop
Succession Planting Catalog descriptions and seed packet instructions offer each vegetable's vital statistics This includes when to first plant in spring, how many days the variety takes to reach maturity, how much space it requires, and if it is frost-tolerant
Succession Planting Avoid diseases and pests depending on what family a vegetable belongs to Avoid planting one member, say tomatoes, in the same spot where a cousin peppers, eggplants, potatoes grew in the previous 3 years Avoid planting in same spot brassica vegetables such as: Kale, Cauliflower, Brussels Sprouts, Broccoli, Kohlrabi, Turnips, Cabbage and Bok Choy
Growing Fall Crops Good time to plant spinach, broccoli, carrots, cabbage, leaf lettuce and radishes First remove left-over debris from the spring planting Before sowing these second crops, turn over the soil and mix in some fertilizer to replace what earlier plants have used up Seeds will germinate quickly in warm weather, will mature as temps start to cool, without struggling through the high heat of summer.
Growing Fall Crops Likely to see less damage from insects in the fall With less heat and humidity fewer fungal diseases will afflict your plants Lots of cool season vegetables actually taste better after a touch of frost It s said that exposure to light frost concentrates the sugars in fall vegetables
Vegetables for Midsummer Planting Know the average first frost date-mature before being killed by cold weather Broccoli, 50-70 days to maturity, survives light frost Brussels Sprouts, 90-100 days to maturity, survives down to 20 degrees Carrots, 70 to 80 days to maturity, sow seed 2 to 3 months before killing frost Carrots are known to taste better when they grow throughout frosts Cabbage, 50-90 days to maturity, survives down to 20 degrees Peas, 70-90 days to maturity, survives high 20 s Radishes, 30-60 days, dig until soil freezes Spinach, 35-45 days to maturity, survives light frost
Summer Vegetables
Garden Peas Season for pea growing is short- sow in the ground early Treat pea seed carefully if cracked are unlikely to germinate Require about sixty days of growth before harvest Young pea plants can withstand light frosts, and will grow at any temperature above 40⁰ F Optimum temperatures for growth are between 55⁰ F and 65⁰ F. Once above 85 peas have poor quality
Edible Pod Peas Include snow peas and sugar snap peas Snow pea pods are thin and tender, eaten when there are still only tiny traces of peas inside This type of pea is usually associated with Asian cuisine
Harvesting Peas To harvest shelling peas, observe the plants carefully, sampling the crop each day, once the pods have begun to fill with peas Optimum pea harvest occurs when peas are slightly larger than the dry seed you planted Will be sweet, tender, thin-skinned, and non-starchy Once peas have reached maturity, they will quickly be inedible within one to three days
Mr. Pea Sheller
Peas Powdery mildew, a foliar disease common in hot weather, can be a problem for peas Leaves and pods can become covered in a whitish mold Choose resistant varieties, and start peas early to avoid hot weather Leafless and semi-leafless vines may be less prone to disease because of improved air circulation through the plants
Onions Direct sow onion seeds early in the season. After they emerge, thin to 3-4 apart Onions can also be planted from sets Plant them as soon as possible in the spring Transplants can tolerate light frosts Plant when temperatures reach 50⁰ F Plant about 2 deep and 3-4 apart Storage onions grown in MN generally are long-day types that require 14 or more hours of daylight to form bulbs
Onions Onions requires a good supply of nitrogen But, too much nitrogen results in late maturity, large necks that are difficult to cure, soft bulbs, green flesh, and poor storage quality Side dress fertilizer after root systems are well-developed once or twice during the growing season with urea at a rate of 1 pound per 25 feet of row Onions are shallow-rooted and require constant moisture. Proper watering will enhance good production Stop watering when bulbs have reached full size and tops have fallen
Harvesting Onions Harvest onions when about half the tops are falling over and dry Can be left in the ground for several days if the weather will be dry and warm Or brought indoors to cure and kept in a warm (75-90 F), wellventilated area for 2-4 weeks until outer bulb scales are dry and the neck is tight Inadequate curing will result in decay during storage Store in a cool, dry area in a mesh bag, bushel basket or flat cardboard box with some holes punched it. Do not let them freeze. They will start to sprout if kept above 40 F.
Onion Varieties Early-Candy, Norstar Main-Copra Late-Sweet Sandwich, Walla Walla Sweet Candy
Carrots Scarlet Nantes Carrot Grow best in a deep, loose soil that retains moisture yet is well-drained. Do not grow well in acid soils Nitrogen recommendations: about ¾ to 1 cup of urea/100 sq. ft. Apply half during seed bed preparation and sidedress the other half in mid-season
Carrots Sow seeds when soil temperature is above 60⁰ F For a continuous supply of carrots, put in 2-3 plantings spaced three weeks apart Till soil to soften and aerate the ground in order to grow long and straight carrots 10-14 days to germinate Gently mulch to retain moisture this will speed germination Bolero Carrot
Carrots Varieties: Scarlet Nantes Chantenay Sugarsnax 54 Early Yaya Nelson Bolero-excellent storage Carrots prefer a sandy loam soil. Heavy soils cause the carrots to mature slower and the roots will end up unattractive Once plants are 1 tall, thin 2 apart
Problem-Forked Carrots Soil should be well drained and loose to prevent forking and stunting of the root growth Forking may also be due to rocky, stony or heavy soil
Aster Yellows Common symptoms of this disease are hairy roots, yellow tops and bitter taste The disease is spread by plant-sucking insects called aster leafhoppers Once plants are infected nothing can be done to cure the plant
Tomatoes Heat-loving vegetables that require long, frost-free season and 6-8 hours of full sun Two types of tomatoes: 1. Determinate or bush-type: generally do not need pruning, staking, or trellising. Plants stop growing and fruit ripens within a certain time period 2. Indeterminate, or climbing: will need some type of support, such as cages, stakes, or trellises. Should be pruned for best results
Planting Tomatoes If you grow your own-sow seed indoors around April 15 th When plants are about 5 inches tall, start hardening them off so that they will adapt well when transplanted outdoors To harden off: Reduce watering Place plants outside where they will receive a couple of hours of sunlight and are protected from wind Gradually expose them to more sunlight over the next week or two, bringing them indoors if night temperatures approach freezing
Planting Tomatoes Purchase healthy non-spindly transplants At the nursery: pull plant out of the pack and look at roots Transplant outdoors in a sunny area after danger of frost has passed and soil has warmed Tomatoes can be transplanted so that some of the stem is placed below the soil line Space determinant tomatoes 24 inches apart Indeterminate types no closer than 3 feet
Plastic Mulch
Plastic Mulch Advantages Advantages Increased soil temperature Reduced soil compaction Reduced fertilizer leaching Reduced drowning of crops Reduced evaporation Cleaner product Root pruning eliminated Reduced weed problems Earlier crops Increased growth Disadvantages Costly to remove Greater initial costs Increased moisture management Increased soil erosion between plastic Increased weeds in plastic holes close to crop
Red Plastic Mulch for Tomatoes Increased yields up to 20% in tomatoes Similar to black and white plastic mulch-warms the soil, prevents erosion, and retains moisture. Ability to reflect certain red shades of light back into the plant, accelerating fruit production and increasing yield Far-red light wavelengths from the plastic bounce back up to tomato plants, the phytochromes tell the tomato fruit to grow more and faster For best results Allow several feet of the red showing on either side of the plant or row Use determinate tomato plantstheir smaller size means they may maximize the amount of light reflected from the plastic
Indeterminant Tomatoes 1. For the first month or so, all of the sugar produced is directed towards new leaf growth. During this stage, indeterminant tomatoes grow very rapidly, doubling their size every 12 to 15 days. 2. Eventually, the plants make more sugar than it can use, which signals the plant to make new branches and to flower. If unsupported the increasing weight of fruit and multiple branches forces the plant to lie on the ground. 3. A vigorous indeterminate tomato plant can easily cover a 4- by 4-foot area. 4. By season's end, it will be an unsightly, disease-wracked tangled mess.
Pruning Tomatoes Encourage a strong main stem by removing all suckers below the first flower cluster Best accomplished by ensuring each leaf has plenty of room and is supported off the ground When growth is extremely dense, many leaves are forced into permanent shade, reducing the amount of sugar they produce More stems = more but smaller fruit A pruned and staked plant will produce larger fruit two to three weeks earlier than a prostrate one
Supported Indeterminant Tomato
Container Tomatoes If you don t have room for a large plant that needs staking or cages, choose a bush variety such as Bush Celebrity or Patio Princess Grow one plant in a container that is at least 12 wide and deep Be ready to water daily during the heat of the summer Patio Princess
Tomato Disease Early blight is one of the most common occurring disease in Minnesota Causes leaf spot and when severe enough, leaves will drop Staking and mulching are important for control-keeps foliage and fruit from contacting soil Mulching including plastic cuts down on "soil splash" onto lower parts of the plant. Note the 'target' appearance of concentric rings
Blossom-End Rot in Tomatoes Is a physiological disorder, not a disease Appears as blackened, leathery spots on the fruit bottoms Caused by calcium deficiency, usually induced by uneven soil moisture Use mulches to conserve moisture When needed give plants adequate water Tomato plants need about 1.5 of water a week during fruiting
Tomato Sunburn Fruit is susceptible to sunburn Fruit develop white patches if there is not enough leaf surface to cover fruit and protect them from sunlight exposure during hot, dry weather
What about Grafted Tomatoes? Grafting is taking the top (scion) of any tomato variety seedling and attaching to a specialized hybrid rootstock grown specifically for its vigor and disease resistance Grafted tomatoes bring together excellent production and disease resistance We ve seen a yield boost of 30 to 50 percent, Johnny s Selected Seeds. Sources-Burpee and Jungs
Suggested Tomato Varieties For our area grow varieties that will mature in 85 days or less Select varieties that have the VFNT designation-have resistance to 4 common tomato diseases Less acid variety try Golden Jubilee Heirloom varieties They are grown for a variety of reasons, but mostly for their taste, which is widely perceived to be better than modern tomatoes Have a shorter shelf life and are less disease resistant than most commercial tomatoes. Brandywine, an Amish heirloom since 1885, is legendary for its rich flavor
Gape Tomatoes Grape tomatoes-often sweeter than standard tomatoes-eating quality of these varieties hard to beat All America Selections vegetable winner-juliet One-ounce tomatoes are produced in clusters Fruit is elongated and has glossy red skin Improved quality for not cracking
Growing Watermelons and Cantaloupe Need three things to grow great watermelon: hot sunny location, fertile well drained soils, bees and water Direct sow or plant transplants Transplanting can add 2 to 4 weeks to the growing season Sensitive to root disturbancegrowth will be retarded if transplants are not properly managed Honeybees must pollinate the yellow watermelon blossom
Growing Watermelons Melon seeds germinate best between 70 and 90 degrees F but can be sown when the soil temperature is above 65 degrees Planting in cooler soil favors soil borne root diseases which can decimate or stunt melons-cold intolerant Average planting date is approximately May 20 in Minnesota Select melon varieties that will ripen under your conditions. Short season types ripen between 65 and 75 days. Full season types ripen around 85 days Grow in rows, 8-12 feet apart Plant the seeds ½ to 1 deep Plant 2 to 3 seeds in groups 24-36 apart within the row Thin to the best plant per group
Growing Watermelons In a month, a vine may spread to as much as 6-8 feet. Ready to harvest within 3 months Determine ripeness by a pale or buttery yellow spot on the bottom or a thump that sounds like your leather boot Also, can cut out a triangle shaped piece, eat it and taste for ripeness Melon quality is a function of the sugar content of the fruit. High sugar content is achieved by avoiding stress
Plastic Mulch Advantages with Melons Advantages Increased soil temperature Reduced soil compaction Reduced fertilizer leaching Reduced drowning of crops Reduced evaporation Cleaner product Root pruning eliminated Reduced weed problems Earlier crops Increased growth Disadvantages Removed at end of the season and often can t be reused Degradable mulches have been developed but rate of degradation is difficult to manage Greater initial costs Increased moisture management Increased soil erosion between plastic Increased weeds in plastic holes close to crop
Cantaloupe/Muskmelon There is technically a difference, but often the names are used interchangeably Cantaloupe requires 35-45 days to mature from flowering, depending on the temperature As the fruit matures the skin surface netting gets rough, the background color of the fruit turns from green to yellow Tendrils (which look like curly strings) on the stem dry and turn brown
Cantaloupe/Muskmelon At harvest twist the fruit at which point it will (slip) from the vine Do not wait for the melons to separate from the vine on their own Sugar content will not increase after harvest Pick cantaloupe as they ripen as they will not all ripen at the same time Cantaloupe will store for 1-2 weeks if held at 45-50 F
Thank you for Attending Steven R. Poppe University of Minnesota West Central Research and Outreach Center Horticulture Scientist poppesr@umn.edu 320-589-1711 http://wcroc.cfans.umn.edu