Question
Hi Jim. Here is a question for you, hope you can help. I live in RI, last fall I dug up parts of my front lawn and reseeded, I did more reseeding this Spring, so I only put down Starter Fertilizer on the new areas, the problem I'm having is the newly seeded areas are not as green as the other parts of the lawn, it's more of a light green with some brown to it, so basically you can see the areas that I reseeded last year. I have sprinklers, so the lawn is watered regularly, do you have any suggestions on how to get the reseeded areas greener? Do you think not using Turfbuilder or some sort of fertilizer on the new areas is the cause of this problem? When I fertilize in Sept and Oct, do you think that will help for next year? Thanks for your help!

Answer
Hi Bob,

>>"...areas are not as green ..?"

We like our domestic lawns to be 'hyper-green'; applying fertilizers is expected to optimize the grass's natural or wild-state greeness.  The foliage of grasses, like trees and other plants, can consist of more than just a single 'phyto-pigment', and this is what determines the over-all greeness in the healthy plant's leaf.

Your lawn appearance problem is probably not related to the fertilizing efforts entirely because so many turf-grasses these days are highly cultivated and far removed from the wild-types. Some have been bred to optimize a leaf-color factor.

This 'patch-works syndrome' you describe is becoming more of a problem where lawns are regularly re-seeded with new 'high-tech turf-grass hybrids',...and with cool-climate grasses in particular.

When re-seeding a lawn, you should try to match the established cultivar as close as possible.
Often, the home-owner will have no idea what a 'named hybrid' grass-type is or if his lawn is seeded with such.  The results of mixing cultivars can be a patchwork appearance even with a single grass species in use; to explain more about this,....


Lawn grasses, like many living things humans work to improve through genetics and breeding, come in species and also cultivar or 'varietal-types' hybrid variations.  The cultivars are often patent-protected and even copy-right named.

A grass Genus such as 'The Fescues' (Genus 'Festuca') can have many species with one or more being an individual regularly 'cultivated' turf-grass.  And these can also have variations and sometimes a sub-specie designation (the botanists are always hashing over the details). The species will each consist of a Genus and species designation (a 'binomial classifying system'), and these days, more often, also a third 'cultivar/varietal' designation-name.

A good example of this naming game might be this:
Genus: Festuca
species: arundinacea
cultivar: "Kentucky-31"


So, a lawn grass specie such as 'Festuca arundinacea' (common 'Tall Fescue') can  have many named cultivars through careful breeding and hybrid crossing.  In this manner a named cultivar-hybrid of this grass type (or any other so horticultured and entering the competition for the markets) can be defined by such parameters as drought and disease resistance, mature growing height, leaf-shape, stem qualities, flower details, seed-production,  over-all texture,....and,...leaf color.  The horticulturalist plant-breeders work to make this process as scientific as possible and have ways to measure the differences evermore precisely.

Some grasses have variable 'optimal greeness' and some even have other various hues and phyto-pigments that make them interesting and marketable. This 'color factor' of course is independent of blanching and browning due to physiologic or pathologic conditions and refers to the 'healthy plant's' mature leaf texture and color.  Again,... it can indeed be the main cause having  re-seeded areas not matching the old stand exactly.  From the over-view, it can look like a patch-works even though one thought the new seed was thought to be the same grass-type.  It is 'species-wise', but not 'hybrid-wise' the same marketed cultivar.

This patch-works can be an aggravation for the 'purist' who wants that extended carpet-like lawn.  There is no cure except to start over with a high-purity seed of a named hybrid.  Once you do get a consistent stand, be sure you keep a record of the named hybrid used so you can match everything with re-seeding events.  

If it is a brand-new home and lawn, you may be able to contact the home-builder or his landscaper to find out what the grass-type and cultivar was when you bought the house.  Web-search with the botanical name to find-out what cultivars of a grass specie are available with patent-protected and purity tested seed.

Another possibility with this patch-works syndrome is an un-even distribution of a nitrogen containing fertilizer.  With available nitrogen above 20% (the 'N' value in the N-P-K ratings on the bag), the lawn should green-up evenly, unless, as stated, it is a genetic factor causing this not to happen.

You can test this effect of fertilizing by letting the lawn become 'Nitrate hungry'.  This means you will have to let the lawn become optimally wild-state non-green by not feeding for a while.  After several weeks, you can apply a high nitrate fertilizer (I recommend ammonium nitrate with 34% N).  This should make the lawn optimally green with sufficient watering (and it must be well-watered after application).  If you perceive a patch-works appearance in turf-grass coloration with this test, then most likely,....you have a cultivar discrepancy in the stand.  Again, this is something you will have to tolerate or else, you can work to treat the less wanted areas as a weedy patch and then work to establish the same cultivar everywhere.
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I Hope this has answered your question(s)!

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Your Questions and Comments are welcome at ALLEXPERTS.com

___ Jim Gibbs,
    Microbiologist/Botanist