Frequently Asked Questions “FAQ”

Please email us at info@swensongardens.com for any additional questions.

What are Intersectional peonies?

Intersectional hybrid peonies are a cross between a tree peony and a herbaceous peony. They are also called Itoh hybrids. The tree peony is the pollen parent and the herbaceous peony is the pod parent. Intersectionals offer the flower and foliage of a tree peony and the stem strength of a herbaceous peony. Unlike the tree peony, which retains its woody stems throughout the year, the intersectional hybrid stems will die back to the ground in the fall and new stems grow from the root every spring. Intersectional hybrid peonies grow two to three times faster than tree peonies.

What is tissue culture free?

Micropropagation or Tissue Culture is a process which involves in vitro (test tube) germination of plant tissue. This method is used to quickly create very large quantities of plants. The results are varieties that may not be true to name, and present slow growing, weak root systems. Purchasing original rootstock ensures the buyer will receive a much more vigorous peony which is true to name!

What are Garden peonies?

Garden Varieties are our definition of all herbaceous and herbaceous hybrid peonies. Their stems die back to the ground in the fall and new stems grow from the root every spring. Some herbaceous hybrid peonies offer outstanding features such as stem strength, extended bloom time, show-quality blooms, landscape-appealing foliage, and new colors.

What does the term ‘fragrant’ mean?

Fragrance preference can vary from person to person, but some of our favorites include: America, Bartzella, Do Tell, Etched Salmon, Petite Elegance, Rose Pearl, and Sugar N’ Spice.

What does the term ‘cut’ mean?

Some peony blooms can be cut and placed in a vase for many days of indoor beauty. We have noted our favorites with this description. If ‘cut’ is not listed in the description, the bloom wilts quickly when cut and is best enjoyed on the plant.

What does the term ‘landscape’ mean?

Peonies identified as “landscape” feature qualities that make the plant very attractive even after the blooms have expired. These peonies feature beautiful leaf color or formations, symmetrical shape, or outstanding stem color, and provide lovely backdrops for the other plants in your garden.

Can I visit your peony farm?

Yes! Please watch our blog and Facebook page or call us for dates. Peak bloom season is usually late May to mid June. We are open Friday and Saturday from 9a - 5p for two weekends. We are closed Sundays.

Does Swenson Gardens ship or sell potted peonies in the spring?

No. We only ship bare-root peonies in the fall because they reach maturity faster, are more disease resistant, and will acclimate better to your site conditions. For these reasons, purchasing bare root peonies is also a better value for your money.

When is the best time to plant bare-root peonies?

Plant six weeks before the first hard frost. This six-week period allows your bare-root peonies to develop feeder roots for next summer’s growth. Gardeners in USDA Zones 2-5 should plant in early in September to early October. Gardeners in USDA Zones 6-8 should plant in early October to early November. We ship your roots at the best planting time for your USDA Zone.

Is it necessary to mulch newly planted bare-root peonies?

Yes, if you live in USDA Zones 2-4. No, if you live in USDA Zones 5-8.

When is the best time to mulch newly planted bare-root peonies?

Mulch after the ground contains two to four inches of frost. Mulching is required to prevent the roots from heaving in late winter and early spring when the soil is thawing and re-freezing.

When is the best time to remove mulch in the spring?

When tulips first appear, remove half the mulch. Remove the remaining mulch 10 to 14 days later. The new growth should be fine even if the temperature dips to 20 degrees F for three consecutive nights. If it is colder than that, re-mulch and remove when temperature warms up again. If you receive a late frost after the blooms are set, you may lose the blooms that year, but the plant will come back the following spring.

My newly planted bare-root peony did not come up the first spring. What should I do?

First check for new growth under the soil. Gently remove a small amount of soil with your hands until you can feel and/or see the root crown on Garden varieties or the red rubber band on Intersectional hybrid peonies. Be sure the eyes or red rubber band are at the correct depth according to your original planting instructions. If the root has sunk, gently remove the additional soil to the correct depth. Newly planted peonies may not survive if your area received heavy rains in the fall or spring. Because of the wide variations in growing conditions we cannot offer a guarantee on our roots.

My peony buds turned brown and did not flower. What should I do?

A late frost may damage the buds. In that case, you will need to wait until next spring to see blooms. If you did not have a late frost, this may also be a sign that your root was planted too deep. Carefully remove 1 to 2 inches of dirt around the stems after the foliage has been cut down in the fall. Using a shovel to lift the root mass to the correct level may also be helpful.

My peony did not bloom its second year. What should I do?

The first step is to determine the amount of sun the plant is receiving. If it gets less than 8 hours of sun, you should move plant to a sunnier location. If the location has sufficient sun, your peony may have sunk or been planted too deep. After the foliage is cut down in the fall, carefully remove about 1 to 2 inches of dirt around the stems. Using a shovel to lift the root mass to the correct level may also be helpful. Wait until the next spring to see if it has bloomed. If not, you should replant it in another location in the fall. Before replanting, trim roots to 8 to 10 inches long to encourage new growth.

Does Swenson Gardens offer a guarantee for the roots I buy?

Because of the wide variations in growing conditions we cannot offer a guarantee on our roots.

How do I cut peony blooms?

Wait two summers before cutting any bloom and then use the 1/3 rule. In the third and fourth summers, you may cut as many as 1/3 of the blooms and keep 2/3 of the blooms on the plant. The fifth year and beyond, you may cut 2/3 of the blooms and keep 1/3 of the blooms on the plant. Never cut all your peony blooms. The cycle of energy must pass through the blooms before traveling back to the roots. For best results, cut blooms early in the morning and place in warm water mixed with floral preservative. Keep the bouquet out of direct sunlight unless you want the blooms to open quickly. In the evening, place the vase in your refrigerator or a cool dark location. In the morning, remove the blooms and trim 1” off the stems. Wash the vase with a solution of 1 part bleach to 10 parts water. Add fresh water and place the stems in the vase. Continue this process until the blooms are spent.

Should I remove the spent blooms?

Yes, as long as you wait at least 2-3 weeks after the last bloom has turned brown. Removing spent blooms also accentuates the shrub-like characteristics of our varieties noted as “landscape”.

Can I plant newer peonies where my old peonies are now?

Yes, but it requires some work! For each original peony, excavate a three-foot cubic area and remove the dirt to avoid any possible contact with that site. Using new topsoil, plant as noted in our Peony Care section.

When can I move or divide my peony?

Healthy plants do not need to be divided. But if you would like to move or share a division, wait at least three summers and do this work in early September. Cut the root mass in half or quarters, retaining at least 3 to 5 eyes per section and trim the bottom roots until they are about 8 to 10 inches long. Rinse off most of the dirt from the sections and dip them in a solution of 1 ounce of bleach to 10 gallons of water. Rinse and then plant immediately.

What are some organic fertilizers I should use?

We recommend composted cow manure because it releases nitrogen slowly and provides microorganism growth. Milorganite is another excellent fertilizer because it adds trace elements, releases nitrogen slowly, and encourages microorganism growth. For heavy clay soil, use pelletized gypsum as an amendment agent. Because it is a mined mineral it is still considered organic. Amend at a rate of 2 cups per hole into your excavated soil. A single application is sufficient. Cocoa bean shells are also an excellent amendment agent. Why? Because most peony varieties are probably female and they love chocolate! Add one or two shovelfuls to your excavated dirt, mix well, and add back into the hole. Seriously, if you want award-winning blooms, give it a try!

What are some organic fertilizers I should not use?

Both blood meal and composted sheep manure release nitrogen too quickly and are not suitable for peonies. We also do not recommend composted horse manure because of the high nitrogen level. Also, a tremendous amount of weed seed germination can occur if any compost is not wintered for several years.

I would like to grow my peonies organically, but, oh, those pesky weeds! Now what?

The hours we invest into removing weeds are truly a labor of love. However, the labor involved in hand weeding is quite high. This is also one of the main reasons why some of our plants may be more expensive than chemical-, fungicide-, and herbicide-loving growers, nurseries and garden centers. You can grow peonies organically too! Professional grade fabric is an excellent weed barrier because it allows water to pass through and provides air circulation for the soil. Cut a hole large enough for the stems grow and expand as the peony matures. You can also add a thin layer of mulch, but keep it away from the stems to avoid rot. Hand weeding will still be needed occasionally, but the area is much smaller.

What is the best pH level for peonies?

A pH level of 6.8 to 7.2 is ideal. We have noticed greater root growth below neutral (7.0 ph) and greater bloom growth at pH levels of 7.0 to 7.2.

Can someone from Swenson Gardens give a presentation at my garden club?

Yes! Please email us for additional information. We are available during the months of January, February, March and April. Prices vary according to your specific needs and location.

Why are Intersectional hybrid peonies prices so varied?

Thank you for asking! Micropropagated or tissue culture (TC) roots are inundating the U.S. market, which is changing the peony industry. We bought 100 TC roots several years ago as a test, and experienced poor results. Twenty plants died and several were not true to name. This was especially disappointing after waiting four years for the first blooms to appear. As we expected, our plants from original rootstock grew much faster than the surviving TC plants. In addition, many of the TC plants developed a tangled root mass instead of a healthy, branched root structure. This created much waste when dividing because nearly 90% of the root needed to be removed to reach the crown. We are staying on course by selling our customers the highest quality bare root peony from original rootstock. We encourage you to be a wise consumer and know what you are buying. Ask any peony seller questions such as: “Have your plants always been grown in your fields or were they grown in a greenhouse?” “Do you sell original root stock or are these tissue culture roots (micropropogated)?” We GUARANTEE our customers that everything we sell is grown and raised in our fields in Howard Lake, Minnesota from original rootstock.

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