Mills County Extension 61321 315th St; P.O. Box 430

Plant Wise Malvern, IA 51551 712-624-8616 http://www.extension.iastate.edu/mills

Prepared by: Shirley D Miller, Mills County Master Gardener Coordinator and Mills County Horticulture Program Assistant July 2021 and their Beauty Dahlias belong to the (Aster) Have you ever tried to grow Dahlias? They are so family along with daisies and sunflowers. diverse in color, size and style! They are Cavanilles noted three cultivars Dahlia considered a tender perennial in cold regions of pinnata, D. rosea and D. cochinea. Now there are North America. They are only winter hardy in 5,692 records (including species and cultivars) on planting zones 8 to 11. Gardeners in zones 2 to 7 the RHS’s horticultural database, with new cultivars can simply dahlia tubers in the spring and constantly being bred. either treat them as annuals or dig them up and Dahlias range from dwarf ideal for bedding, store for winter. Dahlias love moist, moderate to giants such as Dahlia imperialis found growing in climates. Dahlias brighten up any sunny garden the wild from to Colombia where it can with a growing season that’s at least 120 days long. grow upwards of 6m tall. Some cultivars have flowers that reach beyond dinner plate size at 14 inches across.

They are great plants to grow in a cut flower garden and their beautiful flower heads often last well into WHEN TO PLANT DAHLIAS the autumn, extending the flowering season. In the spring, don’t be in a hurry to plant; dahlias WHERE THEY COME FROM will struggle in cold soil. Ground temperature They were discovered in the 16th-century by should reach 60°F. Wait until all danger of spring Spanish botanists who noted dahlias growing wild frost is past before planting. A good rule of thumb is on the hillsides of Mexico, although paintings and to plant them a little after the tomato plants go in. illustrations suggest that native civilizations had Some gardeners start tubers indoors in containers been cultivating and breeding them much earlier. a month ahead to get a jump on the season. Dahlias were originally grown as a food crop for Medium to dwarf-size dahlias will do well in their edible tubers. Gardeners suggest they taste containers. like a cross between carrot, celery and potatoes. CHOOSING A PLANTING SITE Dahlia coccinea was one of the first species to be Select a planting site with full sun. Dahlias grow introduced into Europe from Mexico in 1789. Abbe more blooms with 6 to 8 hours of direct sunlight. Cavanilles (director of Real Madrid Botanical They love the morning sunlight best. Choose a Garden) named the Dahlia after Anders Dahl, the location with a bit of protection from the wind. Swedish botanist. Dahlias thrive in rich, well-drained soil. The pH level of your soil should be 6.5-7.0, slightly acidic. mulch harbors slugs and dahlias like the sun on If you have a heavier clay soil, add in sand, peat their roots. moss to loosen the soil texture for better drainage. WATERING Large dahlias and those grown solely for cut There’s no need to water the soil until the dahlia flowers are best grown in a dedicated plot in rows plants appear; in fact, overwatering can cause on their own, free from competition from other tubers to rot. After dahlias are established, provide plants. Dahlias of medium to low height mix well a deep watering 2 to 3 times a week for at least 30 with other summer flowers. minutes with a sprinkler. Dahlias need lots of water. Like many large-flower hybrid plants, the big dahlias may need extra attention before or after rain, when open blooms tend to fill up with water or take a beating from the wind. FERTILIZING Dahlias benefit from a low-nitrogen liquid fertilizer such as a 5-10-10 or 10-20-20. Fertilize after sprouting and then every 3 to 4 weeks from mid-summer until early autumn. Do NOT over HOW TO PLANT DAHLIAS fertilize, especially with nitrogen, or you risk small Avoid dahlia tubers that appear wrinkled or rotten. or no blooms, weak tubers, or rot. Pink “eyes” (buds) or a little bit of green growth are PINCHING, DISBUDDING AND DEADHEADING good signs. Don’t break or cut individual dahlia When plants are about 1 foot tall, pinch out 3-4 tubers. The smaller flowering types, which are inches of the growing center branch to encourage usually about 3 feet tall, should be spaced 2 feet bushier plants and to increase stem count and apart. The taller, larger-flowered dahlias should be stem length. If you want to grow large flowers spaced 3 feet apart. If you plant dahlias about 1 try disbudding - removing the 2 smaller buds next foot apart, they make a nice flowering hedge and to the central one in the flower cluster. This allows will support each other. the plant to put all of its energy into fewer but The planting hole should be slightly larger than the considerably larger flowers. Also deadhead as the root ball of the plant and incorporate some compost flowers fade. This encourages more blooms. or sphagnum peat moss into the soil. It also helps WINTER CARE to mix a handful of bonemeal into the planting hole. Dahlia foliage dies back with the first light frost in Otherwise, do not fertilize at planting. fall. The tubers should be dug up before the first Dig a hole that’s about 6 to 8 inches deep. Set the hard freeze and stored indoors. Store them like tubers into it, with the growing points, or “eyes,” your other flowering bulbs, in a cool dark area. facing up, and cover with 2 to 3 inches of soil. As Periodically check them throughout the winter. the stem sprouts, fill in with soil until it is at ground level. Squash Vine Borers Have you had that sick feeling when you go to your garden and see your squash plants wilted down and dying! Most likely it was caused by squash vine borer larvae.

CARING FOR DAHLIAS Tall, large-flowered cultivars will require support. Place stakes (5 to 6 feet tall) around plants at planting time and tie stems to them as the plants grow. Dahlias start blooming about 8 weeks after planting, starting in mid-July. Do not water the tubers right after planting; this encourages rot. Wait until the sprouts have appeared above the soil to water. Do not bother mulching the plants. The

2 Squash vine borers (Melittia satyriniformis) are 1. Apply Bt (Beneficial Bacteria Spray). the larvae of an attractive orange and black sesiid Apply an OMRI certified Bacillus thuringiensis (aka moth that is active during the day. Due to their “Bt”) spray on the leaf stems and main stem of the similar appearance, many people mistakenly plant (not the flowers). assume that adult squash vine borer moths are in Bt is a naturally occurring bacterium found in soils the wasp family. They’re not – they’re moths. Like around the world. Research indicates that it is squash plants themselves, squash vine borers are virtually harmless to non-target species. If you also native to America. Adult squash vine borer spray Bt on the stems and leaves of your squash moths are pollinators. However, they lay their tiny plants once per week, the squash vine borer’s eggs copper-colored eggs on squash plants. or larvae will be killed before the larvae is big enough to harm your squash plants. 2. Mulch the squash plant’s stems. Keep the main stem of the plant covered with mulch as it crawls along the ground. This method helps prevent the adult Squash Vine borer moths from laying eggs on the stems. You can even wrapping the stems of your squash plants in aluminum foil if you do not want to mulch. The point is to hide the main stem from the Squash Vine After 9-11 days, squash vine borer eggs hatch, at moth. If you go this route, be sure to routinely which point the larvae chew their way inside the check the rest of your plant since borers also lay squash plant’s stem and slowly eat the plant to eggs on the leaf stems or undersides of the leaves. death. A single adult female squash vine borer Squash vine borer eggs are small, round, shiny and moth can lay up to 150 eggs in a season! copper-colored, very similar in appearance to How can you tell if your squash plant has been “squash bug” eggs. The difference is that squash killed by squash vine borers? bugs lay multiple eggs in very tight clusters, while Basically here’s how. One day you have a healthy borers will often only lay a single egg in one spot - squash plant. 24-48 hours later, you walk outside to or if laying multiple eggs, the eggs won’t be tightly find a squash plant that is limp and collapsed. clustered. Check for small holes in the leaf stems and/or the If you see either type of egg on your squash plant, main stem of the plant with brown frass around the remove them by hand immediately and smash opening, indicating that you have squash vine them (or drop them into a cup of soapy water. 3. borers! Usually, once the squash plant has gone Grow resistant squash varieties. limp from damage, there is no way to bring it back. Most summer squash varieties are very susceptible This experience can be heart-breaking. to vine borers. However, there are other types of So, if you see a shiny, copper-colored egg on your squash you can grow whose tough, thick stems are squash plant, it’s either a squash borer or a squash not nearly as susceptible to squash vine borers. bug, and the eggs should be removed. Squash in the Cucurbita moschata family are especially resistant. These include Butternuts and Tromboncinos, a vigorous Italian heirloom that can be eaten early as a summer squash or allowed to grow huge to be stored as a winter squash. 4. Perform squash surgery. If you find an obvious entry hole on the stem of your squash plant with frass around it, but your squash plant still appears to be healthy, it’s not to late! You can cut the bore out. First, make a straight incision down the stem of the plant (not across the stem which would sever it) where the hole is located. Cut as little as you have to until you spot the bore, or bores, if there is more than one. Here are some things you can do to prevent or You’re looking for white grubs with a black head. stop squash vine borers from damaging your Remove them with tweezers and dispose of them. squash plants: Then cover the affected area with mulch.

3 It is also an opportunity to see what grows good in your area. And when the exhibitor adds the variety name, you know what to order for your garden next year!

5. Use yellow bowls. Squash blossoms are yellow. So the squash vine borer moths are highly attracted to the color yellow. Place a yellow bowl full of soapy water in the garden. The color attracts the moths to the bowl. They then get trapped in the water and The Floriculture displays are so beautiful. Seeing soon drown. these works of art made by nature can sometimes 6. Use row cover. Row cover is a lightweight fabric be breathtaking! There is a class for nearly that lets sun, water, and air in, but keeps insects everything, from cut flowers to potted plants out. The downside of row cover? It also keeps (including house plants and succulents. The pollinators out. This means you’ll need to play the Horticulture is fun to see as exhibitors bring in their role of a bee. Go outside with a q-tip (or tiny paint perfectly paired vegetables. Seeing a plate with brush) in the morning to pollinate your squash green beans that are lined up matching perfectly, plants by hand. Here’s how. Using your q-tip, heads of cabbage beautifully displayed, largest collect pollen from your male flowers (the ones that zucchini and those veggie oddities- that are don’t appear to have tiny fruit at the base of the strangely shaped! flower) and rub the pollen on the stigma of the female flowers (the ones that have miniature versions of the fruit at the base of the flower). Then cover your plants back up.

Entering your produce or flowers can be exciting and fun. It is also can be a learning experience. The maturity, how to pick, cut and display? Most of this information can be found in the 4H publications Keeping a watchful eye on your garden plants can Harvesting and Preparing Vegetables for Exhibit save you the headache of losing your entire squash and Preparing Cut Flowers and Houseplants for crop. Exhibit. To make things fun for the younger kids, the Mills County Master Gardeners and sponsoring a “Make Summer Time is Fair Time! and Take” workshop at the Mills County Fair, It is always fun to visit the Horticulture building at Saturday, July 10th from 10am to 12 noon, in the any County Fair! To see the garden vegetables and Open Class Block Building in the Floriculture area. flowers that exhibitors have brought in to share with They will be making Pinwheels. There is no cost the world! and the youths get to take their pinwheels home! 4 Here are the dates for the Fairs in our area. • Mills County Fair - July 9-13 • Montgomery County Fair - July 13-18 • Fremont County Fair - July 15-19 • Page County Fair - July 20-25

Out of This World Corn Dip

YIELD: Serves 20 PREP TIME: 20 minutes Sauté: 10 minutes

Make some memories this summer! Go to and INGREDIENTS: Part 1 enter your produce or flowers in your local County 2 (15 1/4 ounce) cans whole corn Fair! After all, you will never know how much fun it 2⁄3 cup finely chopped green pepper is until you enter 2⁄3 cup finely chopped sweet red pepper 2 tablespoons butter 3 tablespoons diced onions

Do You Remember When? Y You salt & pepper to taste You just couldn’t wait until the 4th!! Begging to have 1⁄2 teaspoon Lawry's Seasoned Salt your Dad light the sparklers and hand them to you. 1⁄8 teaspoon garlic powder Happy wasn’t the word for it. As a child you were Directions, Part 1: Jubilant with excitement! The sheer fascination of Melt Butter in a medium sauce pan over medium the sparks flying off the sparkler was amazing! heat. Add onions and sauté for 3 minutes. Maybe that’s part of why as adults we still go to see Add chopped peppers, Lawry's and Garlic power to the 4th of July fireworks. Amazed at how they can pan and sauté for 3 more minutes. make fireworks with circles, hearts and whistles. Drain 1 can of corn and half drain the 2nd can. Add The bright colors in the black night sky, feeling the corn to pan and reduce heat to simmer Heat until Booms as they explode into color! corn is heated through stirring frequently. Let cool. But the meaning behind the fireworks, the Flags Part 2 displayed everywhere, the feeling in your heart 1 (7 oz.) can chopped green chilies knowing you are free to celebrate, free to do almost 1 (6 oz.) can chopped jalapeno peppers - drained anything your heart desires! All because our and save to add for taste forefathers fought for Freedom! Remember to 1/2 cup green onion - chopped Thank our Veterans! Let us never forget! The 1 cup mayonnaise celebration of our Independence from 1776 still 1 cup sour cream resonates to this day! Celebrate because you can! 1 teaspoon pepper 1/2 teaspoon garlic powder 1 (16 oz.) package shredded sharp cheddar cheese 2-3 bags Fritos Scoops corn chips Directions, Part 2: In a large bowl, mix all ingredients except chips. Chill two hours to overnight. Serve with Frito Scoops corn chips. (Part 1 is homemade MexiCorn. You can use 30 oz.’s of canned MexiCorn, instead of doing part 1. Just, drain and add to part 2. 5  To prevent them from wasting energy on producing seed, deadhead your spring bulbs after they are July done blooming. Also, fertilize them. But wait till the leaves have yellowed before trimming them off. UP COMMING EVENTS

 April 5, 2021 Registration Resources for Horticulture information opens for the “International Iowa State University Publications Master Gardener ENT 57 Emerald Ash Bore Management Options Conference”. It is virtual this NCPA 33 Insecticide Options for Protecting Ash Trees year. It will be held September 12-17, 2021 (Cost PM 3074 Finding a Certified Pesticide Applicator for EAB $150.) Follow these two links for more information. PM 1366 Canning: Fruit Spreads About | Registration opens April 5 HS 21 Canning: Salsa  July 4, 2021 Independence Day PM 1368 Canning: Pickles PM 1044 Canning: Vegetables  July 9, through July 13, 2021 Mills County Fair PM 1031 Canning: Meat, Poultry, Wild Game and Fish Open Class Fair Book Mills Fair Schedule 2021 PM 638 Canning and Freezing: Tomatoes  July 14, 2021 - 6:00pm - From fynbos to Savanna PM 1043 Canning: Fruits (and everything in between): Plant conservation in HORT 3084 Peppers South Africa (webinar) PM 1706 Growing Raspberries in the Home Garden  August 11, 2021 - 7:00pm - Seeing Red: How plants HORT 3091 Tomatoes influence coloration in birds (webinar) PD 0054 Tomato Diseases and Disorders PM 1895 Tomatillos PM 607 Suggested Vegetable Varieties for the Garden PM 534 Planting and harvesting times for Garden vegetables PM 666 Weed Management in the Home Garden July Horticulture Publications on-line GARDENING https://www.extension.iastate.edu/store/ListCategories TO DO LIST  Water your garden ISU Hotline Links and Numbers evenly and regularly to Hotlines available for all help prevent split cabbages and tomatoes. Iowa Concern 800-447-1985 Financial questions, legal  Check your summer squash regularly for Squash education, stress counseling, crisis/disaster resources and referral (24 hrs - all days) Bugs. Check the underside of the leaves for eggs. Beginning Farmer Center 877-BFC-1999 Program to match Cover the main stem of the plant with mulch to make beginning and retiring farmers (8 a.m. to 5 p.m.) it harder for the Squash Vine Bore moth to find and Teen Line 800-443-8336 Personal and health-related lay eggs on. information and referral (24 hrs - all days)  Be on high alert for insect pests and diseases. Iowa 2-1-1 211 Resource referral for housing, health, food, These include but are not limited to aphids, family, transportation, employment, education, and legal asparagus beetles, cabbage worms, cutworms, assistance (24 hrs - all days) scale, snails, slugs, leaf spot, mildew, and rust. Hot lines available for Iowa Residents Only  Place row covers or netting over bushes with AnswerLine Toll-free: 800-262-3804 Local: 515-296-5883 Questions relating to home and family (9 am-noon & 1-4 pm) ripening berries to keep the birds from eating them. Iowa Healthy Families 800-369-2229 Health information and  Inspect plants for Japanese beetles, including referral (24 hrs - all days) gourds, pumpkins, and squash. Placing netting over Iowa State University Extension and Outreach does not discriminate your favorite roses and other flowers helps to keep on the basis of age, disability, ethnicity, gender identity, genetic the damage down. information, marital status, national origin, pregnancy, race, color, religion, sex, sexual orientation, socioeconomic status, or statue as a  Check Ash trees for signs of Emerald Ash Bore. U.S. veteran, or other protected classes. (Not all prohibited bases  Keep birdbaths full. Clean and fill regularly with fresh apply to all programs.) Inquiries regarding non-discrimination policies water to help keep from spreading diseases. may be directed to the Diversity Advisor, 2150 Beardshear Hall, 515 Morrill Road, Ames, Iowa 50011, (515)294-1482,  Follow ISU’s “Preserve the Taste of Summer” [email protected] All Other Inquiries may be directed to guidelines for canning and freezing produce, fruits (800)262-3804 and meat. (Links to PM’s under ISU Publications)  Wash Hummingbird and Oriole feeders between fillings. Even when the Orioles slow down on feeding. Once the babies fledge the parents will bring them to the feeders. Orioles love grape jelly and fresh oranges.

6