While I'm new to lawncare, I've been in the landscaping business for 30 years. I'd say 80 percent of the commercial work I've done comes from referrals or because I was already working in the area. Thats going to really limit you from the start. You should already have a website going and stating your launch in the spring. Image and branding and SEO will need to also be mastered before startup. I think this is most important-You need to be able to sell. Outside sales can be brutal. You must have some charisma and a good personallity to have success.
Do you plan on working for Property Management Organizations? I'd be targeting the local ones and avoiding ones on the other side of the country.
With all this being said I'd probably budget around 80k to 100k dollars for your startup. I'd like to see your business model sometime(send me a PM and I'll give you my email) and I wish you good luck.