Which crabgrass do you have, annual or perennial?
As a general rule of thumb pull those weeds as soon as you see them and before they get a chance to set seeds.

You can pull em a few at a time, that's no problem, but don't fill the holes with compost, fill em with a soil or soil blend that most closely matches your native soil. Compost, made up of organic matter, after time, as it decomposes will leave the same holes you intended to fill. Maintaining your bermudagrass for optimum performance during it's growing season will keep those weeds to a minimum.

Follow bermudagrass ABC's for optimum performance.

A. Mow frequently as short as your mower will go, frequently enough that you don't remove more than 1/3 of the grass blades. (I mow @ 1/2" (.500") every 2nd or 3rd day during the growing season.)

B. Water deeply & infrequently. Deeply means at least in inch of irrigation, the goal being to get moisture down 8" to 10" deep in the soil. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. If your grass looks dry before the month/week is up, water longer next time. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds.

C. Fertilize often, every 30 to 45 days, beginning as soon as it comes out of dormancy, using feed grains that are high in protien, including soybean meal, corn gluten meal & cottonseed meal, and include an application of alfalfa pellets either early or late in the season.

Dan

Thanks guys. I will take that advice. One of the things that I forgot to mention is that we are still on watering restrictions, so even though I followed the Bermudagrass recommendations of fertilizing and mowing short and frequently this past summer, watering restrictions prevented me from the B part of the plan.

Thanks again!

Fertilizing often, as often as suggested, is unnecessary and a source of pollution. Feeding your lawn that often is unneceesary and a waste of your money.
Add that compost to the areas you pull weeds from since soil is composed of both minerals and organic matter and a good healthy soil needs both. There are many "weeds" that grow best in soils that lack adequate levels of organic matter. Any soil you spend money on will simply be lots of the mineral portion of the soil you already have and maybe a little bit of organic matter that you need lots more of, so the compost will do much more for new grass growth than would some "soil".

If you were up in the north & dealing with cool season grasses like kimmsr does, then yes, that much feeding would be overkill, but not for bermuda. It really depends on your desired result. You can fertilize or not. Your choice. I've maintained lawns where all I did was mow & let mother nature water & I didn't supplement with any fertilizer, and that's fine, but you absolutely won't have results comparable to a lawn that is being properly fertilized.

Regarding filling holes with compost, I also think that when dealing with cool season grasses & mowing at the highest setting on your mower, you won't notice divots in your lawn... But on my lawn, I've worked hard to make it nice & level and that's really difficult to maintain if you are filling holes with compost. Don't get me wrong... I've topdressed with compost in the past... but for filling a hole, particularly on bermudagrass, where you want a nice flat surface, it's the wrong material to use.

I personally don't use any herbicides or pesticides or chemicals of any kind on my lawn, I follow the cultural practices I outline above and I enjoy outstanding results:
{{gwi:108051}}

See weed, pull weed. Especially before it can seed.

OKC Dan and Kimser both point out good things to keep in mind.

Fertilizing frequently isn't a bad thing in and of itself and OKCDan's gorgeous results show what a high level maintanance program can do when done right.

Kimser is right to remind us all that weekend warriors who aren't knowledgeable and consistent can dump too much of a good thing on a yard and not really be helping the yard all that much while causing unnecessary damage to the environment especially when multiplied by millions of yards.

Moderation in all things. But, mostly, when it comes to yards, be knowledgeable and consistent.

I am certain I did not make myself clear enough: I do not use chemical fertilizers, which is why I posted my question on this forum. (I use soybean meal. I have a thorough understanding of the effect of various fertilizers on water quality due to my years of experience in the water quality field.) Thanks for the advice.

OKC Dan, you mentioned compost is not the way to go to fill in holes to maintain a flat lawn like you have. What did you do to get it perfectly flat like that?

While we anxiously await OKCDan's answer I can point you to a GW thread of how another guy did it. Unfortunately his pictures are gone but here is the link to his post on the lawn forum. Read the thread all the way through to get the best idea of what he did. I started out being very skeptical but the guy taught me a lot about leveling bermuda.

Thanks Dchall, I am off to read that thread now.

Interesting thread, but like you mentioned in that thread itself dschall, pictures explain more than 1000 words and unfortunately we can't see the improvement or before and after pictures. Is that guy Proud_X still on garden web?

He was barely ever here. Try writing to him through his member page.

pkapeckopickldpepprz

To get my lawn flat, I took a mixture of local native soil & builders (or mason's) sand in a wheel barrow. I went to the low spots & throw with a shovel & spread with a landscapers rake & watered in. This process takes a while. You can add about 1/2" each time, making sure to leave at least the green tips of the grass showing through. This is best done as soon as your grass gets growing strong//fast in early summer. You can add more every week. Like I said though, it take patience. It's a long, tedious process, but for lawn geeks like us, we don't care, because what we want is the end result & we're willing to do what it takes :)

Dan

Thanks for returning to the thread Dan. I am wondering if I could try something similar but a 50%/50% mix of that builder's sand and compost sifted very fine through 1/4" hardware cloth so the mixture will be fine enough to fill in low spots without smothering the grass and the compost will be some organic matter to fortify the already sugar sand lot that this yard is.

The odd thing that having a sand lot you'd expect it to be awesome as far as drainage goes. Not so with sugar sand, water will sit on top of it without seepinging into the sand uniformly. Anyone know why this is the case with sand (sugar sand)?

"50%/50% mix of that builder's sand and compost"

The compost will decompose, thus giving you just another low spot there again. That is why Dan used 'native soil'.

Native soil here is sugar sand which is hydro phobic and I am trying my damndest to correct that. Organic matter will from my experience generally correct that. I make plenty of compost to once the compost decomposes adding more will be no problem and organic matter as compost wont flatten out as fast as you might think.

Organic matter does, mostly, get digested (or decomposed as some put it) and that is why you need to keep on adding organic matter. The most bestest way to raise a low level of lawn is to cut the turf in a largish X and turn it back and fill in the depression with some good soil and then put the sod back. This filling should be slightly higher than the surrounding area so as the soil settles the old depressed area will be level.
If there is a raised area that needs to be lowered you do just the reverse, make a big X, pull back the turf, and remove some soil. Putting any kind of soil on growing grass can kill that grass.

Kimmsr, can you explain this cut an X thing? Do you cut the sod under the top of soil like you would filet skin off of a fish?

We're talkin about 2 year old bermudagrass here. Forget about cuttin' an X, just topdress the low areas a few times to bring em up to grade & you'll be fine.... Bermuda roots go very very deep.... trying to cut an X and lift sod (like filet skin off a fish) will cut up the roots & underground runners.... I think if you'd attempt to dig up some of your bermudagrass, you might get surprised to find some roots already 12' deep or more....

My 2 cents

Thanks OKCDan. I was surprised when I tried to lift some of the plugs I planted not too long ago just to see if they were rooted and boy you can't even budge the plugs now. Talk about fast established roots! I like the idea of deep roots, meaning longer but infrequent waterings during the summer, also crowding out weeds.