Question
I have an 800 square foot yard in Cambridge Massachusetts.  It was sodded last year, but the sod failed to take and the coverage now is about 40-50%, mainly in clumps.  The situation is difficult because of a combination of shade (some full sun but no more than a few hours a day) and the damage caused by our dog.  He is a small dog, but high energy and he runs around the yard all the time and tears up the turf - in the worst areas (most shade and where he runs the most), the sod has already been worn down to the plastic netting.  I know the sod failed because of the combination of these factorsm particvularly because it wasn;t a type of grass specially suited to shade.  I also overseeded last fall with mixed results.  

I am at my wits end - it is important to us to have a usable surface that doesn't turn into a mud pit every time it rains, and we have even considered the newer (and prohibitively expensive) types of artificial turf.  But before taking this major step, I want to know if it is at all possible to grow a natural lawn.  I would like to make one final try, reseeding with a specialized seed.  The poa supina "Super Nova" seed - bluegrass specialized for shade - is attractive to me because it repairs itself easily when damaged.

My questions are as follows:

Do you think it is possible to grow a lwan in this area (I know this is difficult to answer without seeing the sight)?

Would a specialized seed like the one I mentioned above have a better chance of surviving than the sod, and is it worth giving a it a shot?

If I do decide to seed, how long until we can allow the dog to use the lawn again (he doesn't dig, but he runs and pivots out there quite a bit)?

How much preparation would the area need - should I seed into the existing lawn and hope the bluegrass eventually takes over or kill the existing lawn and start from scratch?

If I start from scratch, how deep does the soil need to be worked?  How much of an advantage would rototilling be?

I would greatly appreciate any advice you could offer on my situation.

Thanks,
Joe  

Answer
Since your soil probably have been preparred recently (when sodding) I recommend you loosen the top 1" of soil in the bare areas, spread a good quality shade mix, and keep the seed bed slightly damp, but not soaked until germination (sprouting). The seeds need consistent moisture to germinate and must not dry out (same for sod). This may mean watering daily for 10-15 minutes to keep the top 1" of soil consistently hydrated.

once the new grass sprouts, gradually reduce the time between watering and the amount of water you apply. the goal after 4-6 weeks is to water infrequently, but deeply. do not water shallowly/frequently except for during seed germination. The deep, infrequent watering (once per week for 2 hours) will ensure good deep rooting.

I recommend a mixture of fine fescues (hard, chewing, creeping red) maybe with a few percentages of kentucky bluegrass, but not much. KBG is not very shade tolorant and I am not surprised by your lack of success in this area.

Grass generally needs 6 hours of full sun to do well. shade tolorant grass can do with as littles as 2-3 hours or filtered sun. I would think your success is good if you use shade mixes.

Under the canopy of mature trees, the grass may be in competition for moisture in addition to sunlight. therefore, even if it rains, you may need to water deeply under the tree canopies or the grass will loose the competition with the trees. When you water, however, water infrequently and deeply (6 weeks after establishment), e.g. 1-2 times per week for 2 hours. During seed establishment water frequently and shallowly to keep the top soil layers consistently hydrated.

I would not roto till or kill the KBG. The grass which remain is there for a reason: it likes it's conditions. Just overseed bare areas and/or sparsely populated areas with a shade mix.

count on 3-4 week establishment period plus another 2-3 week rooting period. If you sow now, I would let the dog on the lawn in late august/early september. At least try to keep it off the newly seeded areas (temporary fencing ?)