Planting Seeds in a Grapefruit

I found this idea on Pinterest and I'm not sure if it will work or not.  The first part did, so that's great.  Now we just have to wait and see if the seeds grow!  So first we started with a grapefruit beacuse we didn't have lemons AND they are bigger so easier or the kids to handle. 

We went outside and the kids used the spoons to put some dirt into their grapefruit peel. 

 Next they added their seeds.  My daughter put WAY too many in so we just put some of hers into her brothers dirt.  Once the seeds were in, the kids used the spoons to add more dirt.  

Finally when the planting was done, we had to water our grapefruits.  My daughter turned on the tap, added some water and voila!  Her planting job was done.  

 But now we have the problem of watering these plants.  I really don't want to have to use the tap - I just see many things going wrong with that.  I want a simple way that the kids can do to.  Then my husband came up with the idea to use a spray bottle.  Not to hard, just a soft spray and you'll be good to go!  Have fun planting!