A Comparison of Two Broccolis and their Side-shoot Production

 By Yvette Henson, San Miguel Basin CSU Extension

Since 2011, San Miguel Basin CSU Extension Colorado Master Gardeners have grown different crops under different covers in our High Altitude Season Extension (HASE) research trials.  We want to know which covers, if any, extend the season and improve yield and quality for whatever crop we are growing that year.  Another goal of the HASE research beds is to find varieties that perform well in our short and cool summer growing season. 

In 2016, we grew 3 varieties of broccoli under 3 different season extension covers and a ‘control’ (no cover).  We chose varieties that would continue to produce side shoots after the main head had been harvested.  Out of the 3 varieties we chose, ‘Solstice’, ‘Umpqua’ and ‘Nutribud’, ‘Nutribud was our favorite because it had the best yield, flavor and nutrition.

Yield of Broccoli
2016 HASE Broccoli Trials

This year, I grew broccoli in my home garden.  When I was planning my garden, I didn’t know if I still had seeds for ‘Nutribud’, so just in case, I bought some seeds at the garden center of the variety ‘Belstar’, an F1 hybrid. (For this blog what matters is to know that seeds from hybrids usually don’t produce plants that are ‘true to type’)  The seed packet said that ‘Belstar’ would continue to produce side shoots after the main head was harvested.  That is what I wanted- I care more about getting an extended harvest through the season than a single harvest of large heads.  After all, I cut them up to prepare them to eat, don’t you?   And since broccoli is a relatively big plant, I wanted to get as much food out of the space they take up as possible. 

‘Nutribud’ broccoli is an open pollinated variety.  (If you save seeds from an open pollinated variety grown correctly, the next generation of plants from those seeds will come ‘true to type’.)  Dr. Alan Kapuler de-hybridized a hybrid variety called ‘Pacman’ and named it ‘Nutribud’ because in a UC Davis test on nutrition in different broccoli varieties, 'Nutribud' came out highest in free glutamine, a building block of protein: good for the brain and healing for the body!

'Nutribud' broccoli head, 2016 HASE Trials, early August 2016.

Turns out, I did have seeds for ‘Nutribud’ at home so I decided to plant 4 plants of each variety.  3 of the ‘Nutribud’ plants produced full-sized heads at the end of July.  The 'Belstar' broccoli produced full-sized heads by mid-August and both varieties continued to produce side shoots until killing temperatures at the beginning of November. 

First 3 heads of 'Belstar' broccoli
and the second side shoots of 'Nutribud' broccoli, etc.
August 15, 2022.

What blew my mind was the difference in size between the side shoots of the 2 varieties.  ‘Nutribud’ continuously grew bite-sized side shoots from the axils in the leaves after the heads were cut.  However, the ‘Belstar’ plants produced head-sized side shoots from large side branches!  I was amazed because none of the other varieties that we grew in 2016, produced side-shoots the size of broccoli heads!  They all produced smaller shoots, like the ‘Nutribud”. 

'Belstar' side shoot (left) & 'Nutribud' side shoots (right)
September 13, 2022

I didn’t do a thorough job weighing each harvest, especially at the beginning, so I don’t have data to show which variety actually produced the most edible broccoli, but it was close.  I could harvest many 'Nutribud' side shoots weekly but it took several weeks for the 'Belstar' side-shoots to grow to their larger size.  

Last harvest of 'Belstar' side-shoots (bottom)
and next-to-last harvest of 'Nutribud' side shoots (top)
October 21, 2022
An advantage of the ‘Belstar’ would be for gardeners or farmers who want to produce 'heads' over a longer period of time.  The advantage of 'Nutribud' would be nutrition.  I personally love the flavor of 'Nutribud' plus the shoots are very tender.