7/20/2012 - By Matthew Shultz

With the New Year comes a new growing season, and before long, rose producers all over the country will start to pot up new crops. Most growers shoot for target ship dates starting just before Mother’s Day.

There are a couple different ways that growers will produce these rose crops. The easiest way to do this is to be sitting on carryover roses from last year. Most growers will actually use last year’s crop for their first round of shipments, because these plants have already sized up and have received at least one cycle trim. These growers will simply apply a light topdress application in the spring to get them to market. We have a good blend for this application in our database; please contact tech services for the formulations.

The next way rose growers will raise a spring crop is to naturally allow the weather to wake them up from their winter dormancy. This is a common practice for some southern growers; they do not apply any extra heat source or forcing techniques, mother nature runs the show.

These growers will usually buy in bareroot stock plants from out West and can them in Feb-March. As the temperatures warm the plant wakes up and fertilizers start to release. During warm weather in the spring, soil salts need to be monitored and shouldn’t rise above 2.0 EC. Growers producing this way will usually incorporate a CRF charge during canning. Harrell’s also has a couple of good formulations for this application as well, thanks to Brad Sorenson! Please contact tech services for the formulations.

Growers with the luxury of having heated greenhouses go about raising their crops in a completely different way. Heat from an outside source is pumped into a closed greenhouse, so that environmental conditions can be manipulated. Most growers in the northern states utilize heated growing areas to raise high dollar crops like roses. With the added heat comes the need to monitor soil salts that much closer, especially on the warmer spring days.

Leaching may be necessary in some heated growing situations. It is common practice for these types of greenhouses to have roll up sides on them so that they can be vented on warmer days. These crops are usually easier to slow down and speed up, and give the grower the most flexible control on their schedule.

The last and toughest way to produce roses is to sweat them. This is common practice across the mid-Atlantic and how I produced them when I was at CP. Roses are brought in bareroot and canned up. They are placed into covered greenhouses, and then covered by a single layer of poly plastic, commonly referred to as a poly blanket. The extra covering helps to form a warm pocket of air underneath it and the buds will start to elongate within 10-14 days.

Crops will usually finish within 10-12 weeks, so resident crop time can be shortened. The added heat requires extremely close monitoring of soil salts, and crops usually require 1-2 leachings a week while the crops are sweating. Roses just like Easter lilies aren’t tough to produce if you monitor them closely. Contact your Harrell's sales rep for further details!