By Barrietodd
County Down,
United Kingdom 
Earlier today I asked about fertilizing newly planted bulbs in my lawn.
The consensual advice was not to do so lest it affected the bulbs.
Does this mean that I should also not apply autumn lawn fertilizer to over where the bulbs are planted?
Thanks,
Barrie Todd
9 Oct, 2012
Answers
I have brought your follow on question to here in order to keep my replies together and for easier reference!
Quote;Thank you for what is clearly sound advice especially regarding using lawn feed which is high in nitrogen and contains weed killer.
May I assume therefore that this category of lawn feed should be avoided at any time of the year even when the bulbs are dormant?
Have you checked if your lawn feed contains weedkiller?
Regarding avoiding it!
This is not necessary as it is a question of type and timing of your lawn feeding!
For example; there are Autumn lawn feeds and Spring lawn feeds on the market,( free of weedkiller) and there is also Lawn feed & weed treatments.
This is the RHS slant on feeding!
Feeding
In mid-spring (often late March to April), use a proprietary spring or summer lawn fertiliser at the manufacturer’s recommended rates. Feeding the lawn will increase vigour and help prevent weeds and moss from establishing. Apply fertilisers when the soil is moist, or when rain is expected.
If grass loses its vigour and freshness between late spring and late summer (often May to August), repeat the application of spring or summer lawn fertiliser or apply 15g per sq m (½oz per sq. yd) sulphate of ammonia mixed with four times its weight dry soil.
Mixing with soil ensures even distribution and avoids scorching the grass. Apply this mixture in cool, moist conditions and lightly water it in. As an organic alternative, use chicken manure pellets. Repeat fertiliser application a third time if needed six to eight weeks later.
Do not apply spring or summer lawn fertilisers, chicken manure pellets or sulphate of ammonia after August.
They contain too much nitrogen for autumn use, encouraging green leafy growth at the wrong time of year, when it could be damaged by winter cold or pests and disease.
As you can see this fits in with feeding your bulbs so all should be OK.
Regarding the need to use a lawn weedkiller then I would apply this July/August rather than early Spring!
This gives it time to kill the weeds before the onset of winter!
The other reason for doing it then is;
Lawn weedkillers are selective i.e. they are designed to kill weeds not the grass!
Plus the fact at this time of the year there are no leaves on your Narcissus/Daffodils to get affected!
So I think that covers your lawn feeding problem!
But have you considered how you are going to mow the lawn now that you have naturalised the bulbs?
Look at this way; Your Narcissus/Daffodils will possibly emerge in January (subject to the weather) then they will probably take around 4-6 weeks to flower, then a couple of weeks in flower, then you have to leave the leaves in place for at least six weeks after flowering.
So you see that adds up to 14 weeks or three months if you like, meaning at best you can cut your lawn sometime in April, although I find it is more often May!
So if you have scattered your bulbs all over the lawn it is going to look somewhat untidy for a while!
If you plant your bulbs in 'drifts/patches' then you can cut the remainder of the lawn, leaving the planted areas till later!
Just thought I would mention this so that you are prepared for the situation when it comes!...Tg
10 Oct, 2012
I have just read all the comments on this thread and the last query concerns me a bit.....Lawn feed!
Lawn feed is often sold as ....Lawn Feed & WEED so check the packaging to see if this is the case!
In terms of the bulbs needing feeding is certainly not an issue for the moment!
As has been said if the bulbs have been properly prepared prior to selling they do not need feeding.
The best time to feed is when the plants come into bud as by then the plant will have used up the nutrients already in the bulb and this will require replenishing for the following seasons flowers.
Now here is the rub!
Your Narcissus will need a high potash feed when they do get round to needing feeding ( bud formation time) and as I recall, lawn feeds will be high in nitrogen.
This Nitrogen might affect the leaves when they begin to grow,that is they might produce leaves at the expense of flowers, but then again it might not, there is no way of knowing!
You have now naturalised your bulbs meaning that in future the bulbs will be governed by the lawn treatment, so a spring lawn feed rather than an autumn feed might be the best option!
But do ensure that it does not include a weed killer!
I hope this answers your query...Tg
9 Oct, 2012