Cool idea. I've a few agricultural extension office calendars that have been published for turfgrass that I reference. Everything is predicated on location of course.

I wouldn't fertilize in summer unless I irrigate, which I don't. Some folks have different levels of lawn obsession, er, care and time they want to spend on a lawn so the app should reflect that.

Moderate to heavy fertilizer and nutrient applications in the fall are where lawn enthusiasts make their money, and the shoot growth is attenuated so we don't have to mow twice a week. It's a win/win, and sets up for success the next season. One thing that I keep an eye on is average soil temperature. Water soluble N can be applied very late in the season so long as the ground isn't frozen. Guess I don't need an app for that, but it should be part of the program.

High temperatures and drouth on the other hand, are bad times to apply certain herbicides, and weeds are especially resistant to this. You could have an "Alert" type of notice when temps and moisture levels are such that 2,4,D might burn the lawn for example. This is what they mean when they say "product should be applied when weeds are actively growing."; the grass is too.

I think it's a great idea, too, but obviously still has some limitations.

I didn't take "First Day to Seed", "Grub Worm Preventer Deadline" to be suggestions, though - just brackets for date ranges to apply a certain product if you want based on Avg climate data for your area. There's no way for the tool to know if you currently have grubs, or weeds, your soil's pH, or what deficiencies you have in what nutrients. But, if you can incorporate those variables into the data input, then you can specify when to apply treatments. You'd have to build in an user login / account feature, with multiple 'Lawn Profiles' that would contain all the variables for each Lawn or Lawn Area that the user would want to manage (soil type, soil test results incl. pH, N/P/K values, current makeup / problems like Crabgrass, Grubs, etc...).

One thing I noticed with my report was that I had a 'Pre-emergent Herbicide' Deadline in May, but no recommendation as to when to start applying.

Also, check the sort order. All recommendations should appear chronologically from top to bottom, but "May 21" comes before "May 10", "June 13" before "June 6", etc...

There's no way for the tool to know if you currently have grubs, or weeds, your soil's pH, or what deficiencies you have in what nutrients. But, if you can incorporate those variables into the data input, then you can specify when to apply treatments. You'd have to build in an user login / account feature, with multiple 'Lawn Profiles' that would contain all the variables for each Lawn or Lawn Area that the user would want to manage (soil type, soil test results incl. pH, N/P/K values, current makeup / problems like Crabgrass, Grubs, etc...).

Stay tuned :-)

Here is my response to dchall_san_antonio :

I really appreciate you taking the time to look through the site, and provide such detailed feedback. This is exactly the kind of response I was hoping to get. Here are some responses to your comments.

When you open up your lawn plan there is a menu on the right that goes into more detail about each lawn care activity. I think that clicking through this would address some of your comments. I reference this menu in the top paragraph of the planner page, but let me know if you think that I need to be more clear about that.

Spring:

First: If you are going to suggest spring seeding, I would put in some more information about the hazards of that practice. Spring is a horrible time to seed new grass, and mid to late spring is worse and worse.

• Under the Seeding tab, it includes the information that you are referencing here. Let me know if you think it is lacking.

Second: April 11 might be too late for preemergent. Generally the guidance we have been giving here is based on Nature.

• So one thing I need to mention is that any dates listed on the site are based on Normal weather data provided by NOAA, and is for planning purposes only. In a future version I’d like to also incorporate forecasted weather data to give something like a two week look ahead.

Third: ...and please don't get discouraged by my comments - I'm trying to be helpful.

• Not discouraged at all! I really do appreciate the time you put into this.

May 4 is likely to be too early to fertilize. The idea for the spring fert drop is to apply after the initial spring flush of new/fast grass growth.

• Based on this comment I am going to reevaluate the spring fert algorithm. Currently it selects the first date that the Normal average temperature is above 60 degrees. I selected this temperature because the dates it outputs are close to most extension office local recommendations. I will see what I can do for this.

Summer:

First: Grass undergoing summer heat stress can sometimes be overstressed by a dose of chemical fertilizer.

• Fert detail page mentions that the mid summer application should only be done if lawn is properly irrigated.

Recommending insecticide on a lawn with no grubs is irresponsible.

• Totally correct. I am going to modify the paragraph on the Insect Control detail page to say that you should only apply if you have a grub problem.

Fall:

As I recall the summer temps begin to cool off in late August. Is that what your temp monitors suggest for that zip?

• The seeding algorithm looks at daytime and nighttime temperatures and germination time recommendations for the specific grass type and looks for windows of time that meet those requirements. So if you select KBG, it will look for a 30 day window where nighttime temps are above 40, and daytime temps are below 80.

The final fertilizer should be fast release, high N.

• I understand what you are saying here, however so far I have stayed silent on all organic/synthetic and fast release/slow release recommendations. I may decide to change that in the future, but not at this time.

Lastly I notice you said nothing about watering.

• This will be added in a future version!

Here is my response to Ted (Zone 4) IA :

Thanks for your time and feedback! Here are some responses to your comments on the site.

I
wouldn't fertilize in summer unless I irrigate, which I don't.

• Agreed!
  Check out the note on the top of the fertilizer detail page.

Water
soluble N can be applied very late in the season so long as the
ground isn't frozen.

• The
  site looks at the Normal temp data provided by NOAA, and the 2nd
  fall application looks the date two weeks before air temperatures
  get down to 32 degrees. Obviously that date varies year to year, but
  this should give you an idea of when that application should be
  made.

High
temperatures and drouth on the other hand, are bad times to apply
certain herbicides

• Currently
  I have no recommendations for post-emergent herbicides, but I do
  plan to add that in the future.

Here are my responses to Lee Mychajluk :

Thank you for taking the time to offer suggestions and review my web app!

There's
no way for the tool to know if you currently have grubs, or weeds,
your soil's pH, or what deficiencies you have in what nutrients. But,
if you can incorporate those variables into the data input, then you
can specify when to apply treatments. You'd have to build in an user
login / account feature, with multiple 'Lawn Profiles' that would
contain all the variables for each Lawn or Lawn Area that the user
would want to manage (soil type, soil test results incl. pH, N/P/K
values, current makeup / problems like Crabgrass, Grubs, etc...).

• All
  of this is in the works! I really wanted to start very basic, and
  get a good working application before I started to add more
  features. But definitely look for user accounts, and macro/micro
  nutrient recommendations in the future.

One
thing I noticed with my report was that I had a 'Pre-emergent
Herbicide' Deadline in May, but no recommendation as to when to start
applying.

• This
  was intentional, but I think you making the point that I need to
  explain this a bit better. There really is only a deadline for
  pre-emergent herbicide. Different types have different durations of
  protection. Really you want to apply as close to the deadline as
  possible without going past. If you go past the deadline, some
  crabgrass may germinate before the herbicide is applied. Does that
  make sense?

Also,
check the sort order.

• You
  are right. It looks like I have a small bug in the sorting. I will
  check this out and fix it. Thanks!

So, by saying I have a deadline in May to apply pre-emergent, herbicide, is that saying that there would be little chance of crabgrass of germinating prior to that date? Will the 'good' grass (fescue, rye, kbg) have already germinated by this time, or would I be preventing the good grass from germinating as well by applying pre-emergent at that time? (Sorry, this might be a bit off topic.)

You are correct that the deadline means that there is little chance that crabgrass germinates prior to the deadline. You want to have your herbicide barrier in place before then. Whether or not your 'good' grass has germinated by then depends on when you seeded and the type of grass. if you go to the seeding detail page it will tell you what the germination period is for your type of grass. For MOST preemergent herbicides you do not want to apply them until after your grass has germinated. There are some herbicides that are OK to apply during good grass germination (Tenacity is one).

All of this considered, read through the top of the seeding page, as it lists some reasons why you may want to wait for fall to seed. That being said, I always seed my back yard in the spring because my dog tends to tear it up. I either use Tenacity, or just deal with weeds post-emergently.