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Plant Samples

Due to the threat of Boxwood Blight, Rose Rosette and other serious pest/disease issues, the Garden is no longer allowing plant samples to be brought in for identification or diagnosis. These problems can spread to the garden displays and severely impact our living plant collection.

Please help us protect our plants by taking clear photos of the plant you need identified or diagnosed. Images can be emailed to plantinformation@mobot.org or brought to the Plant Doctors at the Center for Home Gardening (Open every day, 9 am - 5 pm).  

For any additional questions regarding samples, please call: 314-577-9562.

Digging and Storing Dahlias, Tuberous Begonias, Cannas and Caladiums

  

Dahlias, tuberous begonias, cannas and caladiums will not survive St. Louis winters outdoors. However, because these plants have specialized underground storage organs such as a tuber, corm or tuberous root, they can be dug up and stored indoors for the winter. In spring, they can be re-planted outdoors. 

In fall, dig non-hardy bulbs after the leaves have yellowed, died back or been killed by frost, but before the ground freezes. This provides the longest possible growing season so the plant can store food for next year's growth. 

Dig dahlias and cut the tops back to 3 inches above the root. Remove loose soil by hand or with a garden hose and discard all damaged or diseased root portions and place upside down in the sun for several hours to dry. Then, store the roots at 40 degrees F. in a shallow container covered with sand, vermiculite or peat moss. If the roots begin to shrivel during winter, sprinkle them lightly with water.

Tuberous begonias, cannas and caladiums should be dug and air dried in a well ventilated area at 70 to 80 degrees. Cannas and caladiums need one week to dry while tuberous begonias need two to three weeks to dry. Once dried remove any foliage. Cover the tubers and tuberous roots with perlite, vermiculite, peat moss or sand. Store cannas and begonias at 40 to 50 degrees, caladiums at 55 to 60 degrees. All do best stored in a cool, dark and humid place with good ventilation. Fruit cellars and cool basements work well. Do not store bulbs in an attic or garage where they may freeze. Check throughout the winter and discard shriveled, diseased, or insect infested bulbs.

Click here to view the visual guide on digging and storing cannas

Seasonal Gardening Tips

  • Continue watering, especially evergreens if soils are dry. 
     
  • The average first frost usually arrives about October 15th - 20th.
     
  • With the exception of tulips, spring bulbs may be planted as soon as they are available. Tulips should be kept in a cool, dark place and planted in late October. Plant spring bulbs among hostas, ferns, daylilis or ground covers. As these plants grow in the spring they will hide the dying foliage. 
     
  • Cannas and dahlias can be dug when frost nips their foliage. Allow the plants to dry under cover in an airy, frost-free place before storage.
     
  • Begin readying houseplants for winter indoors. Prune back rampant growth and protruding roots. Check for pests and treat if necessary. Houseplants should be brought indoors at least one month before the heat is normally turned on.
     
  • Nuts or seeds of woody plants usually require exposure to 3 months cold before sprouting. This may be provided by outdoor planting in fall or "stratifying" in an unsealed bag of damp peat moss placed in the refrigerator.
     
  • Cool-season lawns are best fertilized in fall. Make up to 3 applications between now and December. Do not exceed rates recommended by fertilizer manufacturer. 
     
  • Deadhead annuals and perennials as needed.
     
  • Container grown and B&B trees and shrubs can be planted. Loosen the soil in an area 2 times the diameter of the root ball before planting. Mulch well after watering.
     
  • Autumn is a good time to add manure, compost or leaf mold to garden soils for increasing organic matter content.
     
  • For best bloom later this winter, Christmas cactus, potted azaleas and kalanchoe may be left outdoors until night temperatures drop to about 40 F. 


 Learn more

Enjoy the fragrant blooms of the Ozark Witch Hazel flowering in shrub borders or wooded areas on warm sunny days.
Enjoy the fragrant blooms of the Ozark Witch Hazel flowering in shrub borders or wooded areas on warm sunny days.
Repot any root-bound house plants now before vigorous growth occurs. Choose a new container that is only 1 or 2 inches larger in diameter than the old pot.
Repot any root-bound house plants now before vigorous growth occurs. Choose a new container that is only 1 or 2 inches larger in diameter than the old pot.
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Gardening Help

We have staff available to help you with your gardening questions:

  • Plant Doctors: Master Gardeners and Garden staff can answer your questions in person

    Center for Home Gardening
    Every day, 9 am - 5 pm

     
  • Horticulture Answer Service: Have your gardening questions answered over the phone

    Mon.-Fri., 9 am to 12 pm
    (314) 577-5143
     
  • Plant Information: Email your gardening questions to: 

    plantinformation@mobot.org

    We are currently experiencing a high volume of emails, 
    therefore response time may be delayed. We thank you for your patience and apologize for the inconvenience.
Bloom Time Calendar

See when plants bloom at the Garden: