What makes roses stop blooming?

I’m catching up on yardwork this weekend. I suspected my rose bushes needed to be dead-headed because they did not have very many roses. I was sort of surprised that I didn’t even find very many “hips” but some of the ones I did find were quite large. Between five bushes there were maybe 20 hips. In years past I’ve easily found 3-4 times that number and had to cut them off every few weeks. While I was pruning the roses however, I started wondering about what mechanism would cause the plant to stop blooming once it’s pollinated. 

My knowledge of plants is limited to an elementary school experiment where you place lettuce in dyed water and observe that it pulls up the dye and discolors the leaves. I hypothesized that once a bloom is pollinated, it releases a hormone that causes the veins leading to that bloom to swell and draw water away from other potential buds.

Tonight I did some research to learn what the real mechanism is. Actually this turns out to be a difficult thing to look up. I found lots of “how does pollination work” resources, but only one mention that blooms release a hormone that inhibits bud formation once pollinated. Since I’m used to thinking of plants as pulling water and nutrients upwards, I’m interested in how that hormone would get spread throughout the plant.

I found my answer on the plant hormone wikipedia page. My elementary school experiment was using the xylem vessels of the stems. These are specialized tube-like structures that move water and nutrients upwards from the roots to the leaves through capillary action. Differences in pressure due to evaporation of water at the leaves and high water content near the roots allow the xylem to passively move water. Interestingly, the cells that make up the tubes are dead at maturity [1].  There is a second set of vessels in plants called the phloem. These are living cells of the inner most layer of bark which primarily transport sugars and carbohydrates from the leaves to the roots, a process called translocation. Unlike the xylem, the phloem uses positive pressure to move molecules. Sugar producers push molecules into the phloem’s sieve tubes and sugar sinks actively remove molecules from the sieve tubes [2]. The phloem is also responsible for moving hormones from the blooms to other buds in the plant, thus answering my question of how a bloom can communicate with other parts of the plant.

On a related note, I also learned that I should be fertilizing my roses with high phosphorus fertilizer and not high nitrogen fertilizer [3]. In past years I have used Miracle Gro, but for my roses I should be using a rose-specific fertilizer.

Interesting fact: enormous fruits are made by cutting into the phloem of a branch and then removing all but one fruit from that branch. All the sugar produced is driven to the one fruit leading it to grow much larger than normal [4].

[1] http://en.wikipedia.org/wiki/Xylem

[2] http://en.wikipedia.org/wiki/Phloem

[3]  http://www.gardenstew.com/about23326.html

[4] http://en.wikipedia.org/wiki/Girdling#Agriculture


Pickled Beets!

An important followup on canning safety will be coming soon. I probably didn’t process these long enough. Recommendations are 30-35 minutes. The recipe I used only called for 10. 


Last Saturday I harvested 6 lbs of beets from my garden. I have never had a harvest this big before so I wanted to find a good use for them. I chose to pickle them because that can be done with a boiling-water canner. Canning raw (not pickled) beets requires a pressure canner, which I don’t have.

Planting & Harvesting

I planted Detroit Dark Red Beets on June 5th before heading to Texas for the summer. While I was away, my family watered the garden, but it doesn’t look like the beets got thinned out very much. Since beets are a cool weather crop, I wasn’t sure how they would do during the summer months. Last year I did not have good luck. Thankfully this year was cooler and much wetter.

I harvested the beets on August 17th, 73 days after planting. This species is ready for harvest at 60 days but since I was travelling I was not able to harvest at the correct time. The beets were roughly evenly split between 2, 1.5 and 1 inch diameters. Most of the smaller ones were due to not being planted far enough apart. Leaving beets in the ground too long can make them tougher. During the cooking process they softened up and were easily pierced with a fork. I won’t know for another month if the taste was impacted. 


I looked at several recipes and youtube videos for ideas. I ended up using this recipe since it did not call for many spices.

  • 10 lbs beets (I used 6 lbs)
  • 2 cups sugar
  • 2 cups beet brine
  • 4 cups vinegar
  • 1 tbs pickling salt
  • Whole cloves

I split the beets into large and small sizes to cook separately. Leave 1 inch of greens on the beets while cooking so the skin does not fall off. The large beets cooked for 30 minutes and the small beets for 25. After cooking, I could easily pierce the beets with a fork and the skins fell right off under cold water.

Next I mixed the brine, sugar, vinegar, and salt together and brought it to a boil for 10 minutes. I sanitized half-pint jars (smaller than I expected!) in boiling water for 10 minutes. Then I quartered the beets and put them in jars, added 2 whole cloves, and poured in the brine, leaving 1 inch head space in the jar. The jars were processed in boiling water for 10 minutes. (Research the appropriate time for your area. The recommended minimum is 30 minutes! oops)

I ended up with 6 and a half pints. 


Pickled beets should be stored in a cool dark area. I choose the refrigerator. I’ll let them sit for one month before I sample them. They should keep for up to one year.