Forsythia Watch

[turf_toes]

I'm new at this too, but I think soil temp is not a good indicator because of a few reasons. One you mentioned yourself is the difference between soil temperatures in shady and sunny areas. If you had 2 forsythias, one in your backyard and one in your front yard, would they both bloom at the same time? If they did then soil temp is irrelevant. I think air temperature is more uniform over an area so it easier to work with.

Please correct me if I'm wrong, but my understanding of the gdd tracker is that it takes the max and min temperatures of each day and calculates a gdd value. That number adds up each day until the target is reached. If you could measure the max and min soil temps of each day maybe then we could potentially come up with a formula to better emulate the gdd tracker or more importantly Mother Nature herself.

As Andy said "The "Mother Nature thing" is not a side-effect, it is the main event."

Maybe you guys are misunderstanding where I'm coming from. I looked through the GDD Tracker website and focused on the Crabgrass Preemergence Timer (GDD32) as this is the model they use to recommend preemergent for the various weeds we want to control. From their own website discussion of GDD32, they say:

Proper timing of preemergence herbicides is critical to successfully suppressing summer annual grasses like crabgrass, goosegrass, and foxtail. These grasses need the proper soil temperature and soil moisture to germinate and establish. Eighty percent of the germination will occur when the 0-2 inch depth soil temperature is consistently reaching 60-70 degrees F. Preemergence herbicides need to be applied before the soils reach this optimum range. Therefore this model uses GDD to indirectly measure soil temperatures in a turf situation. As with all the models, discretion and understanding of local conditions should be considered. The target range for this model attempts to predict when the 0-2 inch depth soil temperatures consistently reach 50-55 degrees F and therefore provided adequate time for the preemergence herbicide to be incorporated before germination occurs.

The way I read it, the recommendation from this GDD website as related to when to apply preemergents is SOLELY based on the soil temperature. It got me wondering why all the elaborate modeling and predicting of soil temperature when you can just go outside and stick a thermometer in the ground and find out for yourself.

I'm not trying to be difficult here, but when you guys say don't worry about the soil temps, just look at the forsythias because Mother Nature is taking more things into account, then why doesn't the GDD website tell us to just go look at the forsythias? Are they wrong on this?

Also, my total guess would be that a forsythia bush in colder soil (caused by less sunlight) will most likely not flower as quickly as another bush on the other side of the house in sunlight and warmer soil, regardless of having the same air temps.

I suspect that for 99 percent of the population, it makes more sense to just observe nature and use forsythia as a proxy for soil temperature. It has been proven reliable.

But if you want to spend the money on soil temperature probes, that will work too. Fwiw, a web site that doesn't have a soil probe anywhere in my yard (sunny or shady) is probably the least reliable way of predicting when to apply pre-emergent herbicide. Ymmv.

[ericgautier]

All this cold coming soon is making me slap myself for spraying on Monday. Might be a little early but I had to make a judgement call. Hopefully it doesn't screw me up too much.

I would have sprayed the same time as you if my scheduled allowed it. Better to be early than late.

[osuturfman]

All this cold coming soon is making me slap myself for spraying on Monday. Might be a little early but I had to make a judgement call. Hopefully it doesn't screw me up too much.

I would have sprayed the same time as you if my scheduled allowed it. Better to be early than late.

It's OK to be slightly early with prodiamine and slightly late with dithiopyr (Dimension).

GDD are based on phenology that has been ground tested in many locations on thousands of grasses, weeds, trees, ornamentals, and insects. Using GDD as a reliable indicator is great tool yet, you still need to apply common sense.

If there is a tornado warning in your county, it was most likely recognized by a computer. These days, most people don't head directly for shelter. They may look at the radar or step outside to get a sense of the weather and how it may be changing. The GDD Tracker is like a tornado warning as it is giving you a cue, in real time, that you need to be aware of weather and the conditions around you, in order to take appropriate actions.

[LoneRanger]

It's nice to see you around again, osuturfman.

[bauer time]

All this cold coming soon is making me slap myself for spraying on Monday. Might be a little early but I had to make a judgement call. Hopefully it doesn't screw me up too much.

I would have sprayed the same time as you if my scheduled allowed it. Better to be early than late.

It's OK to be slightly early with prodiamine and slightly late with dithiopyr (Dimension).

GDD are based on phenology that has been ground tested in many locations on thousands of grasses, weeds, trees, ornamentals, and insects. Using GDD as a reliable indicator is great tool yet, you still need to apply common sense.

If there is a tornado warning in your county, it was most likely recognized by a computer. These days, most people don't head directly for shelter. They may look at the radar or step outside to get a sense of the weather and how it may be changing. The GDD Tracker is like a tornado warning as it is giving you a cue in real time that you need to be aware of weather and the conditions around you, in order to take appropriate actions.

These comments make me feel a lot better. Bring on the snow! Calling for over a foot on Tuesday in NJ.

[chrismar]

Who knows if it'll melt by the weekend given the cold temps that are forecasted to follow. Gotta love Mother Nature!

[Pennstater2005]

Western PA about halfway between Pittsburgh and Erie. Forsythia buds but no bloom. Still waiting.

Oh and 4 inches of snow on the ground

[salvas]

Is this Frosythia ?

This is a picture of my yard and judging from Google images I assume the bush i have behind the dogs is Forsythia?

Thanks

https://scontent-iad3-1.xx.fbcdn.net/v/ ... e=59330DE5

[andy10917]

Yes, that's Forsythia.

[Billy]

I think it's important to remember that forsythia bloom is just a phenological indicator: it's a rule of thumb. It's not the end-all-be-all of crabgrass PRE timing. The thing about forsythia bloom is that it generally (but not always) occurs a few days (up to a few wks) before crabgrass germination. Some yrs, it might occur at the same time that crabgrass germinates. Other yea, it might occur a full month before crabgrass germination.

So, instead of trying to time PRE apps with forsythia bloom, I would suggest that a split or sequential strategy beginning soon after snowmelt would set you up well for a good weed Ctrl barrier without being too late. For PREs, too early isn't as bad as too late.

[salvas]

I think it's important to remember that forsythia bloom is just a phenological indicator: it's a rule of thumb. It's not the end-all-be-all of crabgrass PRE timing. The thing about forsythia bloom is that it generally (but not always) occurs a few days (up to a few wks) before crabgrass germination. Some yrs, it might occur at the same time that crabgrass germinates. Other yea, it might occur a full month before crabgrass germination.

So, instead of trying to time PRE apps with forsythia bloom, I would suggest that a split or sequential strategy beginning soon after snowmelt would set you up well for a good weed Ctrl barrier without being too late. For PREs, too early isn't as bad as too late.

Got it!

Especially if using Barricade? Since the half life of it is higher than Dimension?

[HoosierLawnGnome]

full bloom here

[71GTO]

For you guys in the NE or New Jersey in particular would you just put down the pre m as soon as the snow melts off the lawn at this point?

[chrismar]

For you guys in the NE or New Jersey in particular would you just put down the pre m as soon as the snow melts off the lawn at this point?

If the forsythia is blooming.

[HoosierLawnGnome]

For you guys in the NE or New Jersey in particular would you just put down the pre m as soon as the snow melts off the lawn at this point?

If the forsythia is blooming.

I actually sprayed mine on top of a few inches of snow that was still unmelted in the shade. It's still a bit yellow today.

It will eventually find it's way to the soil and get to work.

The forsythia are in full bloom near me.

[71GTO]

Going home yesterday it did not appear to be blooming from what I could see. I was planning on using a granular pre m. I don't know if that would stick around on topi of 6 or more Inches of ice and snow.

[DTockeII]

Anyone in Northern IL happen to have one of these plants or see them regularly? There's nothing by me from what I can tell without visiting the Chicago Botanic Gardens. Just trying to figure out my pre-m timings as this is my first year putting it down

[Pway]

Last year the forsythia in my yard was in full bloom on March 10, which is when I put down dimmension. This year it looked like it was about to bloom until the latest cold snap and hasn't progressed. I'm wondering if it'll be late or if buds were damaged by the snow. I still can't put dimmension down yet either way because about 1/3 of the yard is still snow covered (shaded Areas or where the snow piled from the blower or shovel).

[chrismar]

Still no forsythia blooms in 08807 either. 90% of my yard is clear of snow now. Only the shaded northern areas and hell strip still have snow cover. I think I'm going to move forward with my prodiamine app Saturday as it's supposed to be in the 60s and then rain on Sunday/Monday.

If those areas are still snow covered, can I still spray the prodiamine on the snow? I guess it'll eventually work it's way into the soil, right?

[ericgautier]

I am seeing little blooms by me (08816). So plan is to spray Prodiamine this Saturday. Whatever snow is left, I plan to rake up and spread it around so it melts faster.