As we are now over halfway through winter, it's a good time to get your flower seed orders in. If you're looking for something easy to grow, zinnias are a great option for adding bright color to your summer landscape. They're tolerant of hot temperatures and the newer varieties are increasingly resistant to mildew. Zinnia seed can be started indoors or - even easier - directly sown in the garden after the danger of frost has past. Selecting a variety for your garden can be overwhelming with all the choices. Let's look at which ones have performed well in the K-State trials!
Profusion and Zahara series
For season-long landscape performance, the 'Profusion' and 'Zahara' cultivars are great choices. Both of these series have single and double-flower options and many different colors available. The growth habit of these Zinnias is compact enough to also work in large containers.
Zinnias for cutting
Zinnias are excellent flowers to plant in cutting gardens - they are cheerful additions to any bouquet! The 'Benary's Giant' series comes in many colors and has large diameter flowers on tall (3+ foot) plants. 'Oklahoma' zinnias are a little smaller, but are also loaded with bright flowers. The longer stem length and extended vase life of these cultivars are the qualities that make them ideal commercial cut flower crops as well as an excellent choice for our home gardens.
We get questions about the zinnias pictured on our banner, 'Queen Lime' and 'Queen Red Lime.' The color scheme is not for everyone, as the muted colors do not jump out in the landscape, but they make great cut-flowers.
Miscellaneous good ones
'Bridesmaid' has performed very well in the trials; it displays big double flowers without the leggy growth habit of some other zinnia cultivars. The plants are long-lasting and give a powerful pop of color with the bright yellow blooms.
'UpTown Grape' has only been trialed one year, but so far it looks to have great potential. It has a short growth habit like the 'Profusion' and 'Zahara' series, but the flowers are borne on longer stems, making them stand out above the foliage. Fantastic! The stems are long enough that you can cut some for flower arrangements, though the primary function of the plants would be landscape use.
'Dreamland Red' was impressive in the 2013 K-State trials. They displayed incredible vigor and put on quite a show of large colorful blooms on fairly compact plants.
A zinnia with a different texture is 'Star Orange,' which has very narrow and delicate-looking leaves with great vigor and super floriferousness.
2014 has been declared the year of the petunia! Petunias are some of the most colorful flowers we test in the Kansas State University trials and they can be excellent plants for landscaping and container displays. Here are some ideas on how to incorporate them into your gardens.
Petunias are a great choice for providing that low-growing carpet of color in your garden.
To create a very simple yet powerful landscape display using petunias, you can pair plants with contrasting heights and colors, like the example below of 'Supertunia Vista Silverberry' and Pennisetum 'Vertigo' grass. The light and dark together are very striking, plus the plants have very different textures and growth habits. When planted in a big group, there is a more intense affect than if the plants had been spaced out alternately in the plot.
If you have a favorite color and want to do varying shades of it, it is usually possible to find a petunia to match. The example below pairs the tall Cleome 'Senorita Rosalita' with the petunia 'Supertunia Mini Rose Veined' for a nice study of pink.
The next example combines three very different plants together. A curved line of Juncus 'Blue Mohawk' separates the dark-leaved coleus 'ColorBlaze Royal Glissade' from the petunia 'Supertunia Sangria Charm.' We kept the coleus pruned so that the design can be viewed from either side. Another neat thing about this is that the grass-like Juncus is perennial, so the color combinations could be changed up each year, yet still keep that nice spiky texture in the middle.
Click through the gallery below to see other examples of petunias planted in different ways in the landscape.
Many gardeners love having cascading petunias in their patio planters. Planting them in a pot close to where you sit and relax also enables you to choose varieties that are less... shall we say "dominant" than a cultivar such as 'Supertunia Vista Bubblegum,' which is superb in the landscape, but can quickly overpower a small planter.
For something unique you can try 'Sophistica Lime Bicolor' where no two flowers are exactly alike.
'Supertunia Pretty Much Picasso' is another unusual flower that is well-suited for container gardens.
'Suncatcher Vintage Rose' is one that looked nice in the 2013 trials. (There are so many new petunia varieties entering the market on any given year, it can be hard to keep track!) But container gardening enables you to try specialty colors that otherwise wouldn't get noticed in the landscape.
Care and maintenance
In many areas, the primary pest of petunias is Bud Worm. These little caterpillars eat all the flower petals, leaving your otherwise-colorful flowerbed looking very green. In the K-State University trials we use a spray with spinosad as the active ingredient, which is an organically approved control method.
In western Kansas the soils are often alkaline (high pH), which can cause some petunias to suffer from iron chlorosis. This yellowing of the leaves is a result of the plants not taking in enough iron due to the soil pH. Since there are also annual flower trials at the K-State Agriculture Research Center in Hays, we are able to observe which varieties are most resistant to iron chlorosis. We recommend cultivars like the Tidal Wave series, Shock Wave series, and Supertunias that are on the Prairie Star list. If you suspect your soils have a high pH, get a soil test and consider adding soil sulfur as recommended.
Most of the petunia cultivars on the market today do not need dead-heading, and we do not remove any of the old flowers at the trial sites.
With petunias, maintaining your fertilizer program throughout the summer is very important to keep the plants blooming. As is discussed in the FAQ section, here is our recommendations on fertilizing annual flowers:
Simply put, annuals bloom on new growth. The stem of the plant has to grow a little longer to make room for the next flower. If there's no new growth, there will be no flowers. So you need to give the plants frequent light applications of Nitrogen (N). But be sure to avoid excess - that will lead to all green growth and no flowers. Like everything in life, a little is good but too much can quickly turn harmful. It is also important to know that Phosphorus (P) does not influence flowering. Fertilizers with levels of Phosphorus higher than the amount of Nitrogen should be avoided. An ideal fertilizer for flowers should have a nutrient ratio of 2-1-1 or 3-1-1 (N-P-K) such as 12-4-4
The fertilizer program for the container trials involves mixing in a slow release granular fertilizer at planting time. Then we rely on frequent (at least every two weeks) liquid feeding when the temperatures get really hot in July and August. For the field trials, a granular fertilizer that suits our needs (as determined from a soil test) is applied about every two weeks and watered in with overhead sprinklers.
Find a full list of recommended petunias and other annual flowers on the Prairie Star list, including ones that are best in containers.
We run the annual and perennial flower trials for Kansas State University