Maureen, I gather fresh, dried grass clippings in the fall & "cup shape" it in the cleaned boxes so winter roosting birds have a warmer place to roost than in just a bare box or on a tree limb. We've had bluebirds & downies spend nights in the boxes in winter & tree swallows that come too early also roost in the boxes. I make the cup a bit deeper & wider than birds would for nests. In spring I remove some of it when I see birds showing interest in nesting. This sometimes is helpful if we have a cold, wet, perhaps snowy spring that delays nesting.
During nesting season we may have a lot of rain. Nesting material gets wet or blow fly larvae are so prolific that just lifting the nest to scrape out the larvae isn't enough so the nest grasses need to be replaced. I keep dry lawn clippings or some pulled dry grass just for that purpose. Since blue birds often/usually nest twice I clean out the old nest, sterilize the box & put new grass in. Tree swallows don't ever nest here twice but they leave a real mess in their boxes. To encourage bluebirds, especially if it's getting well along in summer, if they want a different box, it's really important to scrub out swallow fecal matter & other mess & put in fresh"starter" grass. Fritzie On 3/22/2020 3:35 PM, Maureen Cowen wrote: > *What is starter grass?* On Mar 22, 2020 Fritzie Blizzard <job121...@verizon.net> wrote : Bluebirds are checking their dwellings. I have blocked the openings to keep male house sparrows from "fixating" on certain boxes & driving away other box nesters. Bluebirds won't start nesting here just yet &*I already have put new, dry starter grass in the boxes.* Fritzie B., Union Springs -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds 3) http://birdingonthe.net/mailinglists/CAYU.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --