Just let the bulbs do what they want to do. Otherwise you will go mad running in and out covering them with straw and row cover, then removing it because it got too warm, then putting it back with the next cold snap...And rest assured, if you start playing the cover/un-cover game, you will invariably be doing it dressed in a flannel nightgown, the world's ugliest bathrobe, a ski hat and your snow boots. Don't go down that road unless you have a specific plan to scare the neighbors :-) Bulbs do just fine without any extra fussing. Lisa (and yes, I was out there one year in nightgown and boots until I learned my lesson)

Gro-lights have a different colour spectrum from full spectrum lights which have a different spectrum from UV lights. To make matters even more confusing, different plants have differing spectral requirements.... Do a Google for gro-lights and check out of few of the sites you find, there will be tons of information out there on the subject.

Bulbs compared to lamp modules like the Cree CR6 and Sylvania RT6 are at a disadvantage as 1. The LEDs are not forward facing in A19 style bulbs, unlike the CR6 and RT6 modules, resulting in more light being trapped in the can. 2. The modules are engineered to dissipate heat from the LEDs within a recessed can housing. 3. If BR or PAR bulbs are used, the light spread is more constrained. 4. The CR6 has better dimming performance than the A19 and A21 Cree bulbs

Several comments 1. The typical operating temperature for Led diodes is much wider i.e. most should operate between -40 to +140 degrees celsius. Real example The max junction temperature for a Cree XM-L Led diode is ~ 150 celsius or 50 above the boiling point of water. 2. There is a wide selection of LED diodes on the market with a wide range of color, efficiencies, current drive, voltage, ... 3. A LED lamp's longevity is affected by how the lamp/ fixture designer design decisions for example- i. Over driving the current at the expense of lifespan. ii. Which LED components to use - more efficient vs greater max output vs cheaper (given the anticipated production run), ... iii. The quality of the other necessary components - capacitors, resistors, ... iv. The quality of the manufacturing process. SMT (surface mount technology) consistently beats the quality of manual soldering and individual wires. 4. Active cooling (i.e. - fan) is no longer used - not effective or cost efficient, prone to failure and reduces the overall efficiency. The use of the motherboard as a heat sink/ spreader is preferred. The Switch lightbulb utilizes an inert liquid and convection circulation to sink the heat produced. 5. The pricing will drop more when the the LED diode costs are reduced as well as when lighting device designers figure out how to reduce the BOM (bill of materials) cost and simplify the manufacturing process. FWIW, the L prize bulb is not competitive with the Cree bulb (or even the newer Philips LED bulbs) from both a manufacturing and end user consumer standpoint. 6. From an electrical standpoint, the E26 connector is no less efficient than a GU24/ bi-pin connector / wire nuts. 7. The more advanced LED deployments today are done in aircraft, automotive and custom home designs where cost is less of a concern. 8. For the rest, it will take a while before more and better fixtures/ lamps designed with LEDs in mind appear since most folks are used to the traditional glass forms ( bulb, tubes).