August 2019       Volume 9, No. 7
Dear Friends,

What is going through my mind right now is this image: A Garden is a Sea of Flowers is a beloved 1915 watercolor by Ross Sterling Turner in the collection at Boston's Museum of Fine Arts. Some of you may not know that I began my career at the MFA, and as a young staffer in the development office, participated in all the openings, parties and events for five years as part of my work! Even on daily errands around the building, there was always the chance to see new (to me) art that I had not encountered before.
A Garden Is a Sea of Flowers, by Ross Sterling Turner 
Fast forward 40 years, and my own knoll garden has become a sea of flowers. Read on below for the details of how I got my tall Phlox paniculata to perform as the star of the garden! And it's fragrant and a pollinator magnet, too!

Plant Pick:  Beautiful Tall Phlox and How to Grow It

Start with the soil, as always. Phlox paniculata prefers a mineral rich, limy soil, with lots of organic matter. Moisture is preferred over droughty summers, and we certainly had a moist spring this year. Then be sure to site the phlox plants in full sun.

Phlox paniculata ' Franz Schubert' 
My soil test showed low Potassium, as we find in many of your gardens.  This essential nutrient promotes good bloom and strong stems. I've been topdressing all the phlox with Greensand (has 32 trace minerals) and compost every fall. I follow up by mulching with a layer of shredded leaves as a natural winter cover that lasts through the next growing season since I have lots of oak and maple leaves handy. The combination of Greensand, compost, and pre-shredded leaves is irresistible to soil microbes, which now have plenty of food. Compost tea applications have also been part of the recipe for success.
When I have time in the spring, I have thinned the phlox to 5-6 stems to promote better air circulation and reduce the potential for dreaded mildew (the white stuff often coating phlox leaves). This year I didn't have time for thinning! However, it didn't seem to make a difference in this moist year. I think it would make a difference in a droughty season - but I lucked out!

Phlox paniculata
I have literally done nothing else except admire the colors and variety.  Blooms started in July and are still going strong on sturdy stems full of green leaves. Staking has been minimal and was needed only this past weekend after nearly an inch of rain. I will deadhead to prolong bloom into September and discourage unwanted seedlings. The deer took a quick nip in early July, but Roy's effective repellent spray ended what could have been a total wipeout.
I'm growing old fashioned cultivars such as 'Franz Schubert,' 'Old Cellarhole' and 'Flamingo' that came from Perennial Pleasures Nursery in Vermont. Head up to East Hardwick next July for their Phlox Festival, featuring nearly 50 varieties! You may prefer to try the new disease-resistant cultivars such as 'David' (tall white), 'Katherine' (lavender), and 'Jeana' (lavender pink). Fall is a great time to get some Phlox paniculata established for next year!

Drifts of phlox in Priscilla's home garden

Getting Ready for Fall - What will you undertake this year? Plangarden

We've prepared quite a fall checklist and stand ready to help you work through it.  What we do now sets the stage for spring 2020. August is a great time to analyze various sections of the garden and make plans for updating. Here's what we'll be tackling as we move ahead into September:

  • Transplant, divide, remove and add plants through late October (save shrub work for late September but start perennials soon)
  • Rework the position of plants in a section, perhaps implementing more changes in other areas next spring
  • Update bed lines
  • Soil testing in problem spots with little or no bloom, potential high sodium from road salt, new areas to be developed, or areas where conditions have changed
  • Amend soil in October and November, as plants put on their root growth and set buds for next spring, or as part of an earlier fall renovation project
  • Build raised bed vegetable areas, fill with our raised bed mix, and let things "cook" over the freezing and thawing cycles of winter
  • Clean up spent crops early and sow an enriching cover crop that will winterkill; or top off existing raised bed mix, amend, and be ready for an early spring sowing of peas, lettuce and other tasty cold season crops
Please let Kim know (  [email protected]  ) if you'd like our help with any of these timely fall tasks.

Phosphorus - A Primer

Speaking of soil testing time, one result that we often find in soil tests that come back from the lab is bound-up, high levels of Phosphorus. This mineral is very hard to unlock, so this work is undertaken over several seasons. The ideal level of Phosphorus is 75 ppm (parts per million). We often find levels in the 400-500 ppm range!  Or higher!  Insects gravitate to plants with high levels of Phosphorus since their simple digestive systems find them quite attractive. As you reduce Phosphorus, you'll also reduce insect predation.
Phosphorus is essential for bloom, seed set, and root growth. It helps convert other nutrients into usable building blocks for growth. Excessive Phosphorus does not help plants and can pollute nearby natural water sources.
The first thing to do is not to add any more Phosphorus. That means zipping up the bag of Bone Meal, Rock Phosphate, or Superphosphate (this last is a synthetic fertilizer and isn't allowed in an organic program, anyways, per NOFA Organic Land Care Standards).
Instead, we will look at the levels of other minerals in your soil, such as Magnesium, Sulfur, Calcium, and Potassium. Some of these (or all) may be on the low side. So we will look to boost them. Retesting the next year usually shows a reduced level of Phorphorus, meaning that (at last) it has been released to your soil.

Priscilla's Garden To-Do List for Late August into September
  • Finish pruning spring blooming shrubs and trees
  • Enjoy the color of dahlias, native hibiscus, Rose of Sharon and phlox
  • Keep watering anything newly planted last fall or this season
  • Patrol beds for deadheading and weeding through the coming month
  • Deadleaf daylilies as you cut spent stalks, removing yellowed foliage
  • Touch up mulch that was disturbed after pulling large weeds
  • Patrol beds for small seedlings of invasive plants and pluck out
  • Freshen containers with fall interest plants
  • Clean up spent vegetable crops immediately and sow cover crops or mulch with sterilized straw since Nature abhores a vacuum

Let's continue to share garden joys in this late summer time of beauty.  We look forward to seeing you very soon,
Priscilla and the PBOG Crew 

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