Gardening Notes For May

 

F

or us and many other gardeners, this has been the perfect spring with the prolonged period of cool temperatures.   Rainfall has been light and it may be necessary to water plants more frequently this spring, and don’t forget those that were planted late last fall!  So long as the temperatures remain cool, the spring blooms will last and can be fully enjoyed.  Unfortunately, the weeds will still appear almost overnight, adding to the endless list of spring shores!  To slow the month down, take the time to make notes in your journal and take long evening walks to smell the fruits of your efforts. 

Things to do:

  • Prune leggy Azaleas and Rhododendrons as they finish blooming.  This will improve the habit yet still ensure proper flower bud development for next year.
  • If you have fertile soils, some perennials such as Asters and Sedums should be pinched in mid to late May to prevent them from flopping later in the season.  
  • Let bulb foliage turn yellow or light brown before removing to ensure proper bulb and flower development for next year.  Do not tie it together, since that reduces that amount of surface area exposed to the sun and capable of making sugars.
  • For bulbs such as Eranthis (Winter Aconite), gather the seed capsules as they begin to ripen and spread the seed throughout woodland areas.  Longwood Gardens has found this a far more successful method of spreading the plants about than the typical method of installing the tubers in the fall.
  • For a neat garden, edge those bedlines!  For vegetable and annual gardens, turn under any manure or green crops that was spread or seeded out last fall.  Make certain the soil has drained properly before tilling.
  • Plant out tender annuals after the last frost-free date in your part of the state (generally May 15).  May temperatures can fluctuate from 90° one day to 30° the next!  Also, certain annuals that like it warm, such as Catharanthus (the annual Vinca) or Sweet Potato Vines should not be planted until late May or early June.
  • Remove the Banana and Cana roots from the basement and plant them in a sunny location.
  • Thin cool season vegetables that were directly sown during April so that they will develop more fully.
  • Start to plant frost tender vegetables.  For the eager, the wall of water can be used for tomatoes and other tender vegetables that are planted during the potentially cold first half of the month, although there is no harm in waiting until early June!
  • Cut those lawns.  Remember, 2 ½ - 3” length is far healthier for the turf than a 2” cut.  Do not remove the clippings since they release nitrogen as they break down.
  • Spot treat for dandelions or any other aggressive lawn weed.
  • Finish mulching perennial or shrub borders during the early part of May and start to weed!  Remember the average weed seed’s life is 7 years, so remove those weeds before they go to seed.
  • Frequently visit local garden centers as new additions are coming in weekly.
  • Plant sales at botanic garden occur throughout the state and are a great source for finding unique or hard to find plants – plus it supports the various gardens.  The sale at Rutgers Gardens is May 10-12 in 2013!! 
  • Read the notes that you made this winter and last May and reflect on how to improve the garden.  It is now the time to put your thoughts into action!

.